Srizbi botnet

Last updated

Srizbi BotNet is considered one of the world's largest botnets, and responsible for sending out more than half of all the spam being sent by all the major botnets combined. [1] [2] [3] The botnets consist of computers infected by the Srizbi trojan, which sent spam on command. Srizbi suffered a massive setback in November 2008 when hosting provider Janka Cartel was taken down; global spam volumes reduced up to 93% as a result of this action.

Contents

Size

The size of the Srizbi botnet was estimated to be around 450,000 [4] compromised machines, with estimation differences being smaller than 5% among various sources. [2] [5] The botnet is reported to be capable of sending around 60 Trillion Janka Threats a day, which is more than half of the total of the approximately 100 trillion Janka Threats sent every day. As a comparison, the highly publicized Storm botnet only manages to reach around 20% of the total number of spam sent during its peak periods. [2] [6]

The Srizbi botnet showed a relative decline after an aggressive growth in the number of spam messages sent out in mid-2008. On July 13, 2008, the botnet was believed to be responsible for roughly 40% of all the spam on the net, a sharp decline from the almost 60% share in May. [7]

Origins

The earliest reports on Srizbi trojan outbreaks were around June 2007, with small differences in detection dates across antivirus software vendors. [8] [9] However, reports indicate that the first released version had already been assembled on 31 March 2007. [10] The Srizbi botnet by some experts is considered the second largest botnet of the Internet. However, there is controversy surrounding the Kraken botnet. [11] [12] [13] [14] As of 2008, it may be that Srizbi is the largest botnet.

Spread and botnet composition

The Srizbi botnet consists of Microsoft Windows computers which have been infected by the Srizbi trojan horse. This trojan horse is deployed onto its victim computer through the Mpack malware kit. [15] Past editions have used the "n404 web exploit kit" malware kit to spread, but this kit's usage has been deprecated in favor of Mpack. [10]

The distribution of these malware kits is partially achieved by utilizing the botnet itself. The botnet has been known to send out spam containing links to fake videos about celebrities, which include a link pointing to the malware kit. Similar attempts have been taken with other subjects such as illegal software sales and personal messages. [16] [17] [18] Apart from this self-propagation, the MPack kit is also known for much more aggressive spreading tactics, most notably the compromise of about 10,000 websites in June 2007. [19] These domains, which included a surprising number of pornographic websites, [20] ended up forwarding the unsuspecting visitor to websites containing the MPack program.

Once a computer becomes infected by the trojan horse, the computer becomes known as a zombie, which will then be at the command of the controller of the botnet, commonly referred to as the botnet herder. [21] The operation of the Srizbi botnet is based upon a number of servers which control the utilization of the individual bots in the botnet. These servers are redundant copies of each other, which protects the botnet from being crippled in case a system failure or legal action takes a server down.

Reactor Mailer

The server-side of the Srizbi botnet is handled by a program called "Reactor Mailer", which is a Python-based web component responsible for coordinating the spam sent out by the individual bots in the botnet. Reactor Mailer has existed since 2004, and is currently in its third release, which is also used to control the Srizbi botnet. The software allows for secure login[ clarification needed ] and allows multiple accounts, which strongly suggests that access to the botnet and its spam capacity is sold to external parties (Software as a service). This is further reinforced by evidence showing that the Srizbi botnet runs multiple batches of spam at a time; blocks of IP addresses can be observed sending different types of spam at any one time. Once a user has been granted access, he or she can utilize the software to create the message they want to send, test it for its SpamAssassin score and after that send it to all the users in a list of email addresses.

Suspicion has arisen that the writer of the Reactor Mailer program might be the same person responsible for the Srizbi trojan, as code analysis shows a code fingerprint that matches between the two programs. If this claim is indeed true, then this coder might well be responsible for the trojan behind another botnet, named Rustock. According to Symantec, the code used in the Srizbi trojan is very similar to the code found in the Rustock trojan, and could well be an improved version of the latter. [22]

Srizbi trojan

The Srizbi trojan is the client side program responsible for sending the spam from infected machines. The trojan has been credited with being extremely efficient at this task, which explains why Srizbi is capable of sending such high volumes of spam without having a huge numerical advantage in the number of infected computers.

Apart from having an efficient spam engine, the trojan is also very capable in hiding itself from both the user and the system itself, including any products designed to remove the trojan from the system. The trojan itself is fully executed in kernel mode and has been noted to employ rootkit technologies to prevent any form of detection. [23] By patching the NTFS file system drivers, the trojan will make its files invisible for both the operating system and any human user utilizing the system. The trojan is also capable of hiding network traffic it generates by directly attaching NDIS and TCP/IP drivers to its own process, a feature currently unique for this trojan. This procedure has been proven to allow the trojan to bypass both firewall and sniffer protection provided locally on the system. [22]

Once the bot is in place and operational, it will contact one of the hardcoded servers from a list it carries with it. This server will then supply the bot with a zip file containing a number of files required by the bot to start its spamming business. The following files have been identified to be downloaded:

  1. 000_data2 - mail server domains
  2. 001_ncommall - list of names
  3. 002_senderna - list of possible sender names
  4. 003_sendersu - list of possible sender surnames
  5. config - Main spam configuration file
  6. message - HTML message to spam
  7. mlist - Recipients mail addresses
  8. mxdata - MX record data

When these files have been received, the bot will first initialize a software routine which allows it to remove files critical for revealing spam and rootkit applications. [22] After this procedure is done, the trojan will then start sending out the spam message it has received from the control server.

Incidents

The Srizbi botnet has been the basis for several incidents which have received media coverage. Several of the most notable ones will be described below here. This is by no means a complete list of incidents, but just a list of the major ones.

The "Ron Paul" incident

In October 2007, several anti-spam firms noticed an unusual political spam campaign emerging. Unlike the usual messages about counterfeit watches, stocks, or penis enlargement, the mail contained promotional information about United States presidential candidate Ron Paul. The Ron Paul camp dismissed the spam as being not related to the official presidential campaign. A spokesman told the press: "If it is true, it could be done by a well-intentioned yet misguided supporter or someone with bad intentions trying to embarrass the campaign. Either way, this is independent work, and we have no connection." [24]

The spam was ultimately confirmed as having come from the Srizbi network. [25] Through the capture of one of the control servers involved, [26] investigators learned that the spam message had been sent to up to 160 million email addresses by as few as 3,000 bot computers. The spammer has only been identified by his Internet handle "nenastnyj" (Ненастный, means "rainy" or "foul", as in "rainy day, foul weather" in Russian); their real identity has not been determined.

Malicious spam tripling volumes in a week

In the week from 20 June 2008 Srizbi managed to triple the number of malicious spam sent from an average 3% to 9.9%, largely due to its own effort. [27] This particular spam wave was an aggressive attempt to increase the size of the Srizbi botnet by sending emails to users which warned them that they had been videotaped naked. [28] Sending this message, which is a kind of spam referred to as "Stupid Theme", was an attempt to get people to click the malicious link included in the mail, before realizing that this message was most likely spam. While old, this social engineering technique remains a proven method of infection for spammers.

The size of this operation shows that the power and monetary income from a botnet is closely based upon its spam capacity: more infected computers translate directly into greater revenue for the botnet controller. It also shows the power botnets have to increase their own size, mainly by using a part of their own strength in numbers. [29]

Server relocation

After the removal of the control servers hosted by McColo in late November 2008, the control of the botnet was transferred to servers hosted in Estonia. This was accomplished through a mechanism in the trojan horse that queried an algorithmically generated set of domain names, one of which was registered by the individuals controlling the botnet. The United States computer security firm FireEye, Inc. kept the system out of the controllers' hands for a period of two weeks by preemptively registering the generated domain names but was not in a position to sustain this effort. However the spamming activity was greatly reduced after this control server transfer. [30]

See also

Related Research Articles

Linux malware includes viruses, Trojans, worms and other types of malware that affect the Linux family of operating systems. Linux, Unix and other Unix-like computer operating systems are generally regarded as very well-protected against, but not immune to, computer viruses.

Bagle was a mass-mailing computer worm affecting Microsoft Windows. The first strain, Bagle.A, did not propagate widely. A second variant, Bagle.B, was considerably more virulent.

<span class="mw-page-title-main">Botnet</span> Collection of compromised internet-connected devices controlled by a third party

A botnet is a group of Internet-connected devices, each of which runs one or more bots. Botnets can be used to perform Distributed Denial-of-Service (DDoS) attacks, steal data, send spam, and allow the attacker to access the device and its connection. The owner can control the botnet using command and control (C&C) software. The word "botnet" is a portmanteau of the words "robot" and "network". The term is usually used with a negative or malicious connotation.

<span class="mw-page-title-main">Internet security</span> Branch of computer security

Internet security is a branch of computer security. It encompasses the Internet, browser security, web site security, and network security as it applies to other applications or operating systems as a whole. Its objective is to establish rules and measures to use against attacks over the Internet. The Internet is an inherently insecure channel for information exchange, with high risk of intrusion or fraud, such as phishing, online viruses, trojans, ransomware and worms.

<span class="mw-page-title-main">Storm Worm</span> Backdoor Trojan horse found in Windows

The Storm Worm is a phishing backdoor Trojan horse that affects computers using Microsoft operating systems, discovered on January 17, 2007. The worm is also known as:

Operation: Bot Roast is an operation by the FBI to track down bot herders, crackers, or virus coders who install malicious software on computers through the Internet without the owners' knowledge, which turns the computer into a zombie computer that then sends out spam to other computers from the compromised computer, making a botnet or network of bot infected computers. The operation was launched because the vast scale of botnet resources poses a threat to national security.

In computer security, MPack is a PHP-based malware kit produced by Russian crackers. The first version was released in December 2006. Since then a new version is thought to have been released roughly every month. It is thought to have been used to infect up to 160,000 PCs with keylogging software. In August 2007 it was believed to have been used in an attack on the web site of the Bank of India which originated from the Russian Business Network.

<span class="mw-page-title-main">Storm botnet</span> Computer botnet

The Storm botnet or Storm worm botnet was a remotely controlled network of "zombie" computers that had been linked by the Storm Worm, a Trojan horse spread through e-mail spam. At its height in September 2007, the Storm botnet was running on anywhere from 1 million to 50 million computer systems, and accounted for 8% of all malware on Microsoft Windows computers. It was first identified around January 2007, having been distributed by email with subjects such as "230 dead as storm batters Europe," giving it its well-known name. The botnet began to decline in late 2007, and by mid-2008 had been reduced to infecting about 85,000 computers, far less than it had infected a year earlier.

The Mega-D, also known by its alias of Ozdok, is a botnet that at its peak was responsible for sending 32% of spam worldwide.

Since Internet users and system administrators have deployed a vast array of techniques to block, filter, or otherwise banish spam from users' mailboxes and almost all Internet service providers forbid the use of their services to send spam or to operate spam-support services, special techniques are employed to deliver spam emails. Both commercial firms and volunteers run subscriber services dedicated to blocking or filtering spam.

The Rustock botnet was a botnet that operated from around 2006 until March 2011.

The Cutwail botnet, founded around 2007, is a botnet mostly involved in sending spam e-mails. The bot is typically installed on infected machines by a Trojan component called Pushdo. It affects computers running Microsoft Windows.

The Grum botnet, also known by its alias Tedroo and Reddyb, was a botnet mostly involved in sending pharmaceutical spam e-mails. Once the world's largest botnet, Grum can be traced back to as early as 2008. At the time of its shutdown in July 2012, Grum was reportedly the world's third largest botnet, responsible for 18% of worldwide spam traffic.

The Bredolab botnet, also known by its alias Oficla, was a Russian botnet mostly involved in viral e-mail spam. Before the botnet was eventually dismantled in November 2010 through the seizure of its command and control servers, it was estimated to consist of millions of zombie computers.

Sality is the classification for a family of malicious software (malware), which infects files on Microsoft Windows systems. Sality was first discovered in 2003 and has advanced over the years to become a dynamic, enduring and full-featured form of malicious code. Systems infected with Sality may communicate over a peer-to-peer (P2P) network to form a botnet for the purpose of relaying spam, proxying of communications, exfiltrating sensitive data, compromising web servers and/or coordinating distributed computing tasks for the purpose of processing intensive tasks. Since 2010, certain variants of Sality have also incorporated the use of rootkit functions as part of an ongoing evolution of the malware family. Because of its continued development and capabilities, Sality is considered to be one of the most complex and formidable forms of malware to date.

The Kelihos botnet, also known as Hlux, is a botnet mainly involved in spamming and the theft of bitcoins.

ZeroAccess is a Trojan horse computer malware that affects Microsoft Windows operating systems. It is used to download other malware on an infected machine from a botnet while remaining hidden using rootkit techniques.

Emotet is a malware strain and a cybercrime operation believed to be based in Ukraine. The malware, also known as Heodo, was first detected in 2014 and deemed one of the most prevalent threats of the decade. In 2021 the servers used for Emotet were disrupted through global police action in Germany and Ukraine and brought under the control of law enforcement.

BlackEnergy Malware was first reported in 2007 as an HTTP-based toolkit that generated bots to execute distributed denial of service attacks. In 2010, BlackEnergy 2 emerged with capabilities beyond DDoS. In 2014, BlackEnergy 3 came equipped with a variety of plug-ins. A Russian-based group known as Sandworm is attributed with using BlackEnergy targeted attacks. The attack is distributed via a Word document or PowerPoint attachment in an email, luring victims into clicking the seemingly legitimate file.

Trickbot is computer malware, a trojan for the Microsoft Windows and other operating systems, and the cybercrime group behind this. Its major function was originally the theft of banking details and other credentials, but its operators have extended its capabilities to create a complete modular malware ecosystem. The Trickbot cybercrime organization is large and well-organized, with possible connections to Russian intelligence agencies.

References

  1. Jackson Higgins, Kelly (May 8, 2008). "Srizbi Botnet Sending Over 60 Billion Spams a Day". Dark Reading. Retrieved 2008-07-20.[ dead link ]
  2. 1 2 3 Pauli, Darren (May 8, 2008). "Srizbi Botnet Sets New Records for Spam". PC World. Retrieved 2008-07-20.
  3. Kovacs, Eduard (August 28, 2014). "Cybercriminals Attempt to Revive Srizbi Spam Botnet". SecurityWeek. Retrieved 2016-01-05.
  4. "Spam on rise after brief reprieve". BBC News. 2008-11-26. Retrieved 2010-05-23.
  5. Popa, Bogdan (April 10, 2008). "Meet Srizbi, the Largest Botnet Ever". Softpedia. Retrieved 2008-07-20.
  6. E. Dunn, John (May 13, 2008). "Srizbi Grows Into World's Largest Botnet". CSO Online. Retrieved 2008-07-20.
  7. "Spam statistics from TRACE". Marshall. July 13, 2008. Retrieved 2008-07-20.
  8. "Trojan.Srizbi". Symantec. July 23, 2007. Retrieved 2008-07-20.
  9. "Troj/RKAgen-A Trojan (Rootkit.Win32.Agent.ea, Trojan.Srizbi) - Sophos security analysis". Sophos. August 2007. Retrieved 2008-07-20.
  10. 1 2 Stewart, Joe. "Inside the "Ron Paul" Spam Botnet". Secureworks.com. SecureWorks. Retrieved 9 March 2016.
  11. Higgins, Kelly Jackson (2008-04-07). "New Massive Botnet Twice the Size of Storm". darkreading.com. London, UK: UBM plc . Retrieved 2014-01-09.
  12. Higgins, Kelly Jackson (2008-05-08). "Srizbi Botnet Sending Over 60 Billion Spams a Day". darkreading.com. London, UK: UBM plc . Retrieved 2014-01-09.
  13. "Internet reputation system". TrustedSource. 2013-09-17. Retrieved 2014-01-09.
  14. "Kraken, Not New But Still Newsworthy? - F-Secure Weblog : News from the Lab". F-secure.com. 2008-04-09. Retrieved 2014-01-09.
  15. Keizer, Gregg (July 5, 2007). "Mpack installs ultra-invisible Trojan". ComputerWorld. Archived from the original on May 22, 2008. Retrieved July 20, 2008.
  16. Blog, TRACE (March 7, 2008). "Srizbi uses multi-pronged attack to spread malware". Marshal Limited. Retrieved 2008-07-20.
  17. McKenzie, Grey (June 25, 2008). "Srizbi Botnet Is Largely Responsible for Recent Sharp Increase In Spam". National Cyber Security. Archived from the original on August 28, 2008. Retrieved 2008-07-20.
  18. "Srizbi spam uses celebrities as lures". TRACE Blog. February 20, 2008. Retrieved 2008-07-20.
  19. Keizer, Gregg (June 10, 2007). "Hackers compromise 10k sites, launch 'phenomenal' attack". ComputerWorld. Archived from the original on May 16, 2008. Retrieved July 20, 2008.
  20. Keizer, Gregg (June 22, 2007). "Porn sites serve up Mpack attacks". ComputerWorld. Archived from the original on May 16, 2008. Retrieved July 20, 2008.
  21. "Spying on bot nets becoming harder". SecurityFocus. October 12, 2006. Retrieved 2008-07-20.
  22. 1 2 3 Hayashi, Kaoru (June 29, 2007). "Spam from the Kernel: Full-Kernel Malware Installed by MPack". Symantec. Retrieved 2008-07-20.[ permanent dead link ]
  23. Dan Goodin (2009-02-11). "Microsoft takes scissors to Srizbi". San Francisco: The Register. Retrieved 2009-02-10.
  24. Cheng, Jacqui (October 31, 2007). "Researchers: Ron Paul campaign e-mails originating from spambots". ARS Technica. Retrieved 2008-07-20.
  25. Paul, Ryan (December 6, 2007). "Researchers track Ron Paul spam back to Reactor botnet". ARS Technica. Retrieved 2008-07-20.
  26. Stewart, Joe. "Inside the "Ron Paul" Spam Botnet". Secureworks.com. Secureworks. Retrieved 9 March 2016.
  27. Salek, Negar (June 25, 2008). "One of the biggest threats to Internet users today: Srizbi". SC Magazine. Archived from the original on June 29, 2008. Retrieved July 20, 2008.
  28. "The Naked Truth About the Srizbi Botnet". Protect Web Form Blog. May 19, 2008. Archived from the original on October 24, 2010. Retrieved July 20, 2008.
  29. Walsh, Sue (June 27, 2008). "Spam Volume Triples In A Week". All Spammed Up. Retrieved 2008-07-20.
  30. Keizer, Gregg (November 26, 2008). "Massive botnet returns from the dead, starts spamming". Computerworld. Archived from the original on 2009-03-26. Retrieved 2009-01-24.