Which Of The Following Is False In Regards To Denial-of-service Attacks Quizlet

The Earth Wide Web Security FAQ

DISCLAIMER

This data is provided by Lincoln Stein (lstein@cshl.org) and John Stewart (jns@digitalisland.net). The Earth Wide Web Consortium (W3C) hosts this document every bit a service to the Web Community; however, information technology does not endorse its contents. For further information, please contact Lincoln Stein or John Stewart directly.

eight. Securing against Denial of Service attacks

Overview

Q1: What is a Denial of Service assail?

Denial of Service (DoS) is an attack designed to render a computer or network incapable of providing normal services. The most common DoS attacks will target the reckoner'due south network bandwidth or connectivity. Bandwidth attacks alluvion the network with such a high volume of traffic, that all available network resources are consumed and legitimate user requests can not get through. Connectivity attacks flood a reckoner with such a high volume of connexion requests, that all available operating system resource are consumed, and the computer tin can no longer procedure legitimate user requests. The loftier-profile attacks of the week of February sixth, 2000 were primarily bandwidth attacks, and all of the targets were loftier-profile net web sites. A consummate clarification of Denial of Service attacks is available from CERT on http://world wide web.cert.org/tech_tips/denial_of_service.html.

Q2: What is a Distributed Denial of Service assault?

A Distributed Denial of Service (DDoS) attack uses many computers to launch a coordinated DoS set on confronting 1 or more than targets. Using customer/server technology, the perpetrator is able to multiply the effectiveness of the Denial of Service significantly past harnessing the resources of multiple unwitting cohort computers which serve as set on platforms. Typically a DDoS master program is installed on one computer using a stolen account. The master plan, at a designated time, then communicates to whatsoever number of "agent" programs, installed on computers anywhere on the net. The agents, when they receive the command, initiate the attack. Using client/server engineering science, the master program tin can initiate hundreds or even thousands of agent programs within seconds.

Q3: How is a DDoS executed confronting a website?

A website DDoS is executed past flooding one or more than of the site's web servers with so many requests that it becomes unavailable for normal employ. If an innocent user makes normal folio requests during a DDoS set on, the requests may fail completely, or the pages may download and so slowly equally to make the website unusable. DDoS attacks typically take advantage of several computers which simultaneously launch hundreds of thousands of requests at the target website. In order not to be traced, the perpetrators volition break into unsecured computers on the internet, hide rogue DDoS programs on them, and then utilize them as unwitting accomplices to anonymously launch the attack.

Q4: Is in that location a quick and easy fashion to secure confronting a DDoS attack?

No. From a simplistic perspective, the best solution is to secure computers from being hijacked and used as attack platforms. This cuts the problem off before it tin can ever manifest. Thus many experts propose that we "pull together every bit a community" to secure our internet computers from becoming unwitting accomplices to such malicious intruders. Unfortunately, for every business that has the cognition, budget, and inclination to brand such changes, there are many more which lack such resources.

Plus, the attackers are nearly likely going to use non-commercial computers as assail platforms, because they are usually easier to pause into. Academy systems are a favorite, considering they are oftentimes understaffed or the systems are set to minimum security levels to allow students to explore the systems as part of their teaching. Further, this is non just a national trouble. Whatsoever internet server in the globe could be used equally an set on platform.

Still, the simplest and near effective solution for preventing DDoS is through a global cooperative try to secure the internet. The first step in the procedure, therefore, is concerned with scanning your cyberspace computers to make sure they are not beingness used every bit unwitting DDoS assault platforms. This is non just good internet citizenry, yet, considering this likewise serves to certificate and verify that your internet computers are not suspect when DDoS attacks occur.

Q5: Can the U.S. Government make a difference?

Certainly. The authorities could impose many types of restrictions on the net that could greatly limit such types of attacks, at to the lowest degree from U.S.-based computers. Getting on the web could require the equivalent of a "Driver's License", having a website could require the equivalent of a "Commercial Permit", and all ISP's could be tightly regulated, much as the public utilities (Water, Power, etc.) are today. Even so the regime is treading a fine line betwixt limiting criminal activity and limiting economic growth, didactics, freedom of information, and general personal freedoms. For the time being, the U.Southward. authorities appears to be looking for approaches that are consequent with a non-intrusive approach.

For case, President Clinton proposed that nosotros develop an data security "cyber-corps" of contempo higher grads to fight DDoS and other cybercrimes. While this is a sensible proposal, volition there be a blitz of information science grads who will want to join such a group? Informatics students are past and large interested in scientific discipline, not in law enforcement, then if Clinton'south proposal goes through, it will be interesting to see if the government can attract the best of the all-time to join the "cyberpolice".

It should be noted, still, that in all likelihood a more intrusive government role is inevitable if uncontrollable attacks continue. If the government tries to be both helpful and non-intrusive, they may be simply ignored by commercial ventures. For example, during the calendar week of February half-dozen, 2000, a written report from Federal Computer Week revealed "that only two,600 individuals had downloaded a free security tool from the FBI'south Spider web folio. That tool, which detects denial-of-service code, has been available since December."

Stride past Step

Q6: How exercise I check my servers to encounter if they are active DDoS hosts?

Learn 1 or more than filesystem scanning tools to make up one's mind if any of the known DDoS tools are present on your server file system.

Compare the available tools from security tool vendors. Like virus software, DDoS tools become obsolete as new DDoS exploits are invented or existing ones are modified to evade detection. Select a tool that has been recently updated to handle the latest DDoS assail methods.
The FBI offers a tool on their website chosen "find_ddos" that will search the file arrangement for the Trinoo, TFN, TFN2K and Stacheldraht DDoS tools. It is freely bachelor on http://www.fbi.gov/nipc/trinoo.htm. I may be interested in the fact that the FBI does not make the source code for this plan available.

Note that the FBI tool is not guaranteed to take hold of every DDoS binary. If the perpetrator has installed a root package, the find_ddos program may or may not exist able to overcome it. The readme file says, "The tool was written in C and so that it will have minimal reliance on system binaries, and then it will not be impacted by most 'root kits'. Even so, it is susceptible to a kernel loadable module-based root kit."
For more than data about how root kits piece of work, come across http://staff.washington.edu/dittrich/misc/faqs/rootkits.faq.

An alternative scanning tool is freely available on http://www.nessus.org.
Many commercial tools are also available.

Use manual methods to double-check for DDoS action originating from your network (techniques from Kurt Seifried, seifried@securityportal.com).

Fix a filter on the firewall that sits betwixt the web server and the cyberspace connection or upstream connectedness to your Internet service provider. Look for "spoofed" packets, i.due east., packets that do non originate from your network. This is known as egress filtering. If spoofed packets are being generated on your network, at that place is a good chance that a DDoS program is generating them. Trace the packets dorsum to their source, take the computer offline and clean the computer.
Block ports (like 37337) that are typically used to remotely control compromised machines.
Browse your network for open up ports on a regular basis using tools such as nmap or saint - whatsoever changes should be investigated and appropriate action taken.

Q7: What should I do if I find a DDoS host program on my server?

Recognize that the presence of a rogue (Trojan Horse) programme on your system indicates that a vulnerability exists which has been exploited. Other subtle and not and so subtle changes could have been fabricated to the system, and so a complete analysis of your security vulnerabilities is required. While your system may not yet exist displaying any overt problems, this is no reason to soften the incident response approach.
Execute your organization'due south incident response policy. If no policy has yet been put in place, then perform the following emergency steps, at minimum:

Write everything down, starting from the first suspicion of an incident. Depending on the severity of the compromise, this will help you both technically and legally.
Exercise not circulate the information regarding the compromise to your organization. This can non exist helpful, and could atomic number 82 to media interest. Only inform those individuals who can straight assist in helping to prepare the trouble, your manager, and police enforcement officials.
Contact the strongest security experts in your organization for aid. If none are bachelor, ask management to request immediate assistance from a consulting firm that is experienced in incident handling for the operating systems and system software that you are running.
Physically remove the compromised computer from the network (unplug the network cablevision). If the computer is mission-disquisitional, then deploy a hot-fill-in server if bachelor. If no hot-fill-in is available, then downtime is unavoidable.
Backup the compromised computer's file system. Before commencement the backup, dump whatever dynamic information tables maintained by your operating system to standard files and then that they tin can be analyzed later. For example, the lists of currently executing processes, of currently logged-in users, and of current network connections should exist dumped to flat files. Then make two backups of the system using 2 different backup programs.
Shut downwardly the compromised computer.
Re-kickoff the computer.
Reformat the drives used by the arrangement software.
Reinstall the operating arrangement.
Apply all operating system patches.
Perform system "hardening" - this involves establishing operating system-specific settings to negate usually known vulnerabilities.
Restore the file system - do non overwrite any system files, and examine any password files manually before the restore.
Put the computer back on the network.
Cheque all other computers on the network to see if the same vulnerability has been exploited elsewhere.

Q8: How tin I prevent my servers from existence used every bit DDoS hosts in the future?

Recognize and understand the vulnerabilities of internet servers:

Unless special measures take been taken, internet servers have host names and IP addresses that can be hands looked up by anyone on the net.
Many organizations do not put firewalls in front of their net servers, leaving them largely unprotected from many of the probes and attacks that firewalls tin easily stop.
Past default, servers mind for service requests on standard, well known ports, and they naturally attempt to process all requests.
Servers are designed to run unattended, and so in that location is rarely a "user" present who could expect for unusual activity.
Servers often need to exist administered remotely, from off-site, so they are designed to accept remote connections from users with very powerful permissions.
Many servers will reboot automatically later on a shutdown, which is exactly what sure types of exploits are looking for.

If your system has already been compromised, and then backup the filesystem, re-install the operating organisation and restore the filesystem.
Install operating system updates provided past OS vendor.

If the update is security-related, then it is especially crucial to install it.
Be sure to read the vendor's documentation advisedly. Some updates are less well-tested than others, and an update can really harm your system if information technology contains defects.

Secure the servers.

Turn off all unnecessary server services. Many of the services offered by your operating system are non required past your web server, for instance RPC-based services. Adopt the attitude of "deny offset, and then allow". Presume a service should be turned off, unless it is absolutely required.

Get-go determine which of the program-based services can be turned off, such equally FTP, telnet, etc. These services are easily found every bit executable programs in the file system.
Many systems accept been compromised by exploitation of buffer overrun bugs in the RPC services "statd", "cmsd" and "ttdbserverd". These attacks are described in CERT Incident Note 99-04 bachelor on http://www.cert.org/incident_notes/IN-99-04.html.
Next check your operating system's documentation to see if it is providing services at the kernel level which are not visible every bit separate programs. For example, the netmask service may be provided at the kernel level. In this case, determine what parameters can be ready, if any, to plow off kernel level services that are not required.
Contact your operating arrangement vendor to find out if at that place are additional kernel level services that are not in the system documentation, and, if then, how to disable them.
Once all unnecessary services accept been disabled, make cryptographic checksums of the entire system, which can be used later if there has been a suspected breach.

For UNIX-based systems, Tripwire will handle this, available from TSS.
More than data on cryptographic checksums is available on http://www.cert.org/security-improvement/practices/p043.html

Configure the web server software.

Verify that you lot have the latest version of the web server software installed. If your version is old, get the new one and install it before continuing.
Turn off all unnecessary services offered by your web server software. For example, Java support, CGI support, and Server-side Script support should be turned off if they are not required.

Limit concrete access to the server.

Take appropriate action to ensure that the server is only accessible to the designated system administrator(s). All the security in the world can be defeated by a elementary floppy disk if the perpetrator has concrete access to the server.

Q9: How can I prevent my personal computer from being used as a DDoS host?

Recognize and understand the vulnerabilities of internet clients:

Internet clients, i.due east., personal computers connected to the internet, can also be compromised and used every bit agents for DDoS attacks.
Personal computers with full-fourth dimension connections to the internet are especially useful to DDoS perpetrators.
The easiest way and nearly common way to compromise a personal computer is through a voluntary file download initiated past the user - malicious programs posing as screen savers, games, and images are mutual culprits.
The composure of the new personal computer operating systems (due east.g., Windows 98, Windows NT Workstation, Linux) which enable background processing and multi-processing, brand them viable agents for distributed denial of service attacks.

If your system has already been compromised, then backup the filesystem, re-install the operating organisation and restore the filesystem.
Install operating system updates provided by OS vendor.

If the update is security-related, then it is especially crucial to install information technology.
Be sure to read the vendor's documentation carefully. Some updates are less well-tested than others, and an update can really harm your system if it contains defects.

Secure the clients/personal computers.

All internet users on your network, particularly those with fulltime internet connections, must be informed that their computers could exist used as attack agents, and they must exist equipped with the latest detection software.
The new anti-virus updates are now able to detect many rogue DDoS programs. The latest versions of these programs must be downloaded and installed.

Norton'south plan is available on http://www.symantec.com/avcenter/venc/data/w32.dos.trinoo.html
NAI offers similar support on http://vil.nai.com/vil/DoS98506.asp, as do many other vendors.

Annotation that if a rogue program is already operating on the client arrangement, these detection programs may not work.

In the instance of Norton, enable existent-time protection, and then reboot the calculator to check for DDoS agent programs already in operation.

Q10: What is a "smurf assault" and how do I defend confronting it?

smurf is a simple however constructive DDoS set on technique that takes advantage of the ICMP (Internet Control Message Protocol). ICMP is normally used on the cyberspace for fault handling and for passing control messages. One of its capabilities is to contact a host to see if it is "upwardly" by sending an "repeat request" package. The common "ping" program uses this functionality. smurf is installed on a figurer using a stolen account, and and so continuously "pings" one or more networks of computers using a forged source address. This causes all the computers to respond to a different computer than actually sent the packet. The forged source address, which is the actual target of the attack, is then overwhelmed by response traffic. The computer networks that respond to the forged ("spoofed") parcel serve as unwitting accomplices to the set on. The basic characteristics and defense strategies against smurf follow. Farther information is available from CERT. A complete description of smurf past Craig Huegen is bachelor on http://users.quadrunner.com/chuegen/smurf.txt.

Attack Platforms: In order for smurf to work, it must find assail platforms that have IP broadcast functionality enabled on their routers. This functionality allows smurf to send a unmarried forged ping packet and take it circulate to an entire network of computers. To prevent your system from being used as a smurf attack platform, disable IP-directed broadcast functionality on all routers. Generally speaking, this functionality will not be missed.

The attacker may still be able to launch a smurf attack from within your LAN, in which case disabling IP broadcast functionality at the router will have no result. To protect confronting such an attack, many operating systems provide settings to prevent computers from responding to IP-directed circulate requests. Check with your O/S provider for more than data and review Appendix A of the CERT Advisory number CA-98.01 available on http://world wide web.cert.org/advisories/CA-98.01.smurf.html.
In club for the assaulter to successfully take reward of you lot as an attack platform, your routers must allow packets to exit the network with source addresses that practise not originate from your internal network. Information technology is possible to configure your routers to filter out packets which do not originate from your internal network. This is known as network egress filtering.
Internet access provider's should employ network ingress filtering, which drops packets which practise not originate from a known range of IP addresses. Ingress filtering is described in detail in RFC 2267.

Targets: the easiest manner to frustrate a smurf attack is to filter for repeat respond packets at the border routers and driblet them. This volition forbid the packets from hitting the web server and the internal network. Some other option, for those using Cisco routers, is CAR (Committed Access Rate).

Dropping all echo reply packets will foreclose flooding of your network, but it volition not foreclose traffic jams in the pipe from your upstream provider.

If you are the target of an attack, inquire your Internet service provider to as well filter out and drop repeat reply packets.

If y'all exercise not want to completely disable repeat answer, then yous tin selectively drop echo reply packets that are addressed to your high-profile, public web servers.
Auto is a technology developed by Cisco that allows you lot to specify the maximum amount of bandwidth that can exist used by any particular parcel blazon. Using Motorcar you tin can precisely specify the maximum corporeality of bandwidth that can exist used past echo respond packets. For more information, see http://www.cisco.com/warp/public/707/newsflash.html.

Q11: What is "trinoo" and how do I defend against it?

trinoo is a complex DDoS tool that uses "master" programs to automate the control of any number of "agent" programs which launch the actual set on. The attacker connects to the calculator hosting the chief program, starts the master, and the principal takes care of starting all of the amanuensis programs based on a listing of IP addresses. The agent programs then assail one or more targets by flooding the network with UDP packets. Prior to the assail, the perpetrator will accept compromised the estimator hosting the master programs and all the computers hosting the agent program in order to install the software. The bones characteristics of and suggested defense strategies confronting the trinoo DDoS attack follow. A complete description of the trinoo was adult by Dave Dittrich and is available on http://staff.washington.edu/dittrich/misc/trinoo.analysis.

trinoo uses UDP protocol for all communications between the master program and the agents. Intrusion Detection Software tin can look for flows that utilize UDP protocol (type 17).
trinoo chief programs listen on port 27655. The attacker will connect via TCP, typically via Telnet, to the computer hosting the master program to launch it. Intrusion Detection Software can look for flows that employ TCP (type 6) to connect to port 27655.
All communications from main to agents must comprise the cord "l44" (that's the letter l, not the number 1) and will exist directed to the agent's UDP port 27444. Intrusion Detection Software tin check for connections to UDP port 27444. If packets containing the string l44 are existence sent at that place, the reckoner receiving the packets is probably a DDoS agent.
Communications between master and agent are password protected, however currently the password is non sent in encrypted format, so information technology can be "sniffed" and detected. Using the countersign, and the script trinotavailable from Dave Dittrich'due south website, it is possible to positively verify the presence of the trinoo agent. Once an agent is positively identified, the trinoo network can be dismantled:

Utilize the "strings" command on the agent daemon to excerpt the list of primary IP addresses.
Contact all installations serving as trinoo masters to notify them of the incident.
On the master computer, identify the file (by default named "...") containing the list of agent IP addresses and extract the listing.
Disable the agents by sending them a forged trinoo control to close downward. Note that the agents may restart regularly via an entry in the crontab file (on UNIX systems), so the agents may need to exist close downward over and over once more until the possessor of the agent system tin fix the crontab file.
Check for an active TCP connection to the main plan. This indicates alive communication between the attacker and the trinoo chief program. While the assailant is in all likelihood using a stolen account to initiate the attack, information technology nonetheless may be possible to find the assaulter (given high levels of cooperation betwixt the ISP, the phone company, and law enforcement).

If y'all are under trinoo attack, your system will exist flooded with UDP packets. trinoo sends the packets from the same source address to random ports on the targeted host. Detection involves finding multiple UDP packets with the same source IP accost, the same destination IP accost, the same source port, but different destination ports.
An automatic program to notice and eradicate trinoo can be found on http://www.fbi.gov/nipc/trinoo.htm.

Q12: What are "Tribal Flood Network" and "TFN2K" and how exercise I defend confronting them?

Tribe Flood Network, like trinoo, uses a principal plan to communicate with attack agents located across multiple networks. TFN launches coordinated Denial of Service Attacks that are especially hard to counter as it can generate multiple types of attacks and information technology can generate packets with spoofed source IP addresses. Some of the attacks that can be launched by TFN include UDP flood, TCP SYN flood, ICMP echo request inundation, and ICMP directed broadcast. The bones characteristics of and suggested defense force strategies against the TFN DDoS attack follow. A complete description of the TFN was developed past Dave Dittrich and is available on http://staff.washington.edu/dittrich/misc/tfn.analysis. A TFN incident assay from CERT is also available.

To initiate TFN, the attacker accesses the main plan and sends it the IP address of 1 or more than targets. The master program proceeds to communicate with all of the agent programs, instructing them to initiate the attack.

Communications betwixt TFN master programs and agent programs use ICMP echo reply packets, where the actual instruction to be carried out is embedded in the 16-bit ID field in binary format. The use of ICMP (Internet Command Bulletin Protocol) makes package protocol filtering possible.

TFN agents tin be defeated past configuring your router or intrusion detection organisation to disallow all ICMP echo and echo reply packets onto your network. However this will break all internet programs (such equally "ping") that apply these functions.

The TFN master programme reads a list of IP addresses containing the locations of the agents programs. This listing of addresses may be encrypted, using "Blowfish" encryption.

If it is not encrypted, then the agents can be identified from the list.

The TFN agent programs have been found on systems with the filename td and the master programs with the name tfn. They tin can be positively identified by running the UNIX strings command. Come across David Dittrich'south research for details on the output of strings.

TFN agents do not check where the ICMP repeat reply packets come from. Therefore it is possible to forge ICMP packets to flush out these processes.

TFN2K is a more than advanced version of TFN, that "fixes" some of the weaknesses of TFN. A CERT incident analysis is available.

Under TFN2K communications between master and agent may use any ane of several protocols - TCP, UDP or ICMP - making protocol filtering impossible.
TFN2K is capable of sending decadent packets to cause a system to crash or go unstable.
TFN2K tin can defeat egress filtering and ingress filtering by spoofing IP source addresses to make packets announced to come from a neighboring machine on the LAN.
Because this attack tool has just recently been identified, no research (that I could detect) has found any significant weaknesses in the program. Until TFN2K tin be analyzed more completely, the best defense is to:

Harden systems and networks to foreclose your systems from being used as DDoS hosts.
Set egress filltering on the border routers, equally perhaps not all TFN2K source addresses will be spoofed using internal network addresses.
Enquire your upstream provider to deploy ingress filtering.

Q13: What is "stacheldraht" and how do I defend confronting information technology?

Stacheldraht, (German for "spinous wire"), developed by Mixter, is as well based on the TFN and trinoo customer/server model where a master program communicates with potentially many thousands of agent programs. The perpetrator connects to the master program to initiate the assault. Stacheldraht adds the post-obit new features: encrypted communication between the assaulter and the chief program, too as automatic updates of the agent programs using rcp (remote re-create).

Stacheldraht launches coordinated Denial of Service Attacks that are peculiarly difficult to counter as it tin can generate multiple types of attacks and information technology can generate packets with spoofed source IP addresses. Some of the attacks that can be launched by Stacheldraht include UDP flood, TCP SYN flood, ICMP repeat request flood, and ICMP directed broadcast. The basic characteristics of and suggested defense force strategies confronting the Stacheldraht DDoS attack follow. A complete description of Stacheldraht was developed by Dave Dittrich and is bachelor on http://staff.washington.edu/dittrich/misc/stacheldraht.analysis.

To initiate Stacheldraht, the aggressor accesses the master program and sends it the IP address of one or more targets. The master program proceeds to communicate with all of the agent programs, instructing them to initiate the attack.

Communications between Stacheldraht principal programs and agent programs are primarily carried out using ICMP echo and echo answer packets.

Stacheldraht agents can be defeated by configuring your router or intrusion detection system to disallow all ICMP echo and echo reply packets onto your network. All the same this will also break all internet programs (such as "ping") that utilize these functions.

The amanuensis plan reads a listing containing the IP addresses of valid chief programs. This list of addresses is encrypted, using "Blowfish" encryption. The agent attempts to contact each of the master programs on the listing. If it is successful, then the amanuensis plan performs a test to determine if the arrangement information technology is installed on volition permit it to modify ("spoof") packet source addresses. These two activities can exist detected by configuring intrusion detection systems or sniffers to wait for their signatures:

The agent will send each main an ICMP echo respond packet with an ID field containing the value 666 and data field containing the string "skillz". If the master receives the parcel, information technology volition reply with an ID field containing the value 667 and information field containing the string "ficken". The amanuensis and primary periodically "touch base" by exchanging these packets. By monitoring for these packets, Stacheldraht can exist detected.
Once the agent has constitute a valid master plan, information technology will execute a spoofing examination by sending the master an ICMP packet with a spoofed source address. It uses the false address "3.3.three.3". If the chief receives the spoofed packet, it volition reply to confirm that source address spoofing is working with the cord "spoofworks" in the ICMP packet data field. Past monitoring for these values, Stacheldraht can as well exist detected.

Stacheldraht agents do not check where ICMP echo reply packets come from. Therefore it is possible to forge ICMP packets to flush out these processes.
The Stacheldraht agent programs, too as TFN and trinoo can be detected using a C program written by David Dittrich and available on http://staff.washington.edu/dittrich/misc/ddos_scan.tar.

Q14: How should I configure my routers, firewalls, and intrusion detection systems against DDoS attacks?

Against Smurf

To determine if yous are an attack platform:

monitor for packets which do not originate from your network.
monitor for high volumes of echo request and echo respond packets.

To prevent existence used as an attack platform:

disable IP-directed broadcast functionality on all routers.
filter out packets which do not originate from your internal network.

To mitigate attacks:

filter for echo reply packets at the border routers and drop them.
for Cisco routers, use Auto to specify the maximum corporeality of bandwidth that can be used by repeat respond packets.

Against trinoo

To make up one's mind if you are an attack platform:

UDP protocol is used for all communications between the principal program and the agents. Filter for flows that employ UDP protocol (type 17).
attackers connect to the primary program over TCP at port 27655. Filter for flows that use TCP (type vi) to connect to port 27655.
master to agent communications must contain the string "l44" (that's the letter fifty, not the number 1) and will exist directed to the agent's UDP port 27444. Filter for connections to UDP port 27444 containing the string l44.

To prevent being used every bit an set on platform:

filter out packets which do not originate from your internal network.

To mitigate attacks:

theoretically, y'all could filter for sequences of UDP packets with the same source IP address, the same destination IP address, the same source port, but unlike destination ports and drib them. Whether current firewall technology is up to this task is not known to the author.

Against TFN and TFN2K

To determine if you are an set on platform:

monitor for packets which do not originate from your internal network.

To prevent beingness used every bit an set on platform:

disallow all ICMP repeat and repeat reply packets onto your network (note that this will pause all internet programs that use these functions).
filter out packets which practise non originate from your internal network.

To mitigate attacks:

(under research)

Against Stacheldraht

To determine if y'all are an assault platform:

filter for ICMP repeat answer packets with an ID field containing the value 666 and data field containing the string "skillz" or ID field containing the value 667 and data field containing the cord "ficken".
filter for ICMP parcel source address "3.iii.3.three" and the cord "spoofworks" in the ICMP packet information field.

To prevent being used every bit an attack platform:

disallow all ICMP echo and echo reply packets onto your network (note that this will intermission all internet programs that utilize these functions).
filter out packets which do not originate from your internal network.

To mitigate attacks:

(under research)

Lincoln D. Stein (lstein@cshl.org) and John N. Stewart (jns@digitalisland.net)

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