Sophos Security Threat Report 2007 Malware
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Security threat report Security threat report 2007 Overview 2006 saw increasingly surreptitious behavior on the part 2006 at a glance of cybercriminals who have found more cunning ways to hide their activities. Copycat websites that only the keenest eye can detect as fake, spam campaigns that mutate in • Malware authors continuing to turn their a matter of seconds in order to evade detection, phishers backs on large-scale attacks in favor of replicating voicemail systems to duplicate the switchboards more focused attacks of legitimate companies – these are just three examples of • Explosive growth of web-based downloaders the rapidly changing nature of the threat. to spy on users The total number of different malware threats protected • Total number of different malware threats against by Sophos was 207,684, with Mytob at the top of protected against – 207,684 the list of malware families. Malware continued to spread • 41,536 new pieces of malware detected by via spam, instant messages, hacked websites, email, and Sophos network shares. In addition, the web became a signifi cant source of threats, being overrun by spyware, adware, • Trojans outnumbering Windows viruses potentially unwanted applications and undesirable websites. and worms 4:1 The motivation, as with all other spreading methods, was • New mass-mailing worm, Stratio had over fi nancial gain, with perpetrators trying to steal confi dential 1000 unique variants in November information or generate income through compromised PCs. • Email containing infected attachments – As malware writers continued to attempt to use malicious down to 1 in 337 code in a covert fashion to evade detection, the trend away • Most spam continuing to be relayed by from infected email that we saw in 2005 persisted. The poorly protected US computers proportion of infected email was down from 1 in 44 in 2005 to just 1 in 337 in 2006. Increasingly complex ways of getting private information Only 34% of businesses think 2007 will from users and businesses has seen more rapidly evolving spam campaigns, complex operational methods, and a raft be a better year for security than 2006. Source: Sophos online poll, December 2006 of new scams. These have been met with new laws and an increased vigor in applying them, but the threat landscape remains challenging for the year ahead. 1 Sophos security threat report 2007 Malware Malware growth rates In 2006, Sophos detected 41,536 new threats. Malware 8000 writers continued to fi nd new ways of infecting computers and duping users into handing over confi dential information 7000 throughout the year. There was a particular surge at the 6000 end of the year, with November seeing 7612 new threats – nearly four times November 2005’s number of 1940. 5000 Sophos does not expect the growth in malware to taper off 4000 in 2007. If anything, we expect to see even more devious attempts to steal information with the end goal of fi nancial 3000 gain. 2000 The spike in the graph above is attributable to the emergence 1000 in 2006 of a family of malware called Stratio, also known as Stration or Warezov. This mass-mailing worm saw major 0 growth and over one thousand unique variants of it were Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec spammed out in November. (Stratio is described in more New malware threats each month in 2006 detail on page 4.) Top ten email threats Sophos has a global network of tens of thousands of 0% 5% 10% 15% 20% 25% 30% monitoring stations capturing data on the latest viruses W32/Mytob spreading via email. W32/Netsky Although the proportion of infected email fell from 1 in 44 W32/Sober in 2005 to just 1 in 337 (0.3%) in 2006, there was W32/Zafi nevertheless some high-profi le malware dropping into users’ W32/Nyxem inboxes. Worms such as Mytob, Netsky and Sober spread widely via email in 2006. W32/Bagle W32/MyDoom 1 Mytob W32/Stratio The list of top ten malware families reveals that variants of the Mytob worm continue to plague insuffi ciently protected Troj/Clagger users around the globe. Mytob fi rst emerged in March W32/Dref 2005, yet people are still being infected by this email-aware worm. 18-year-old Farid Essebar, a Russian-born resident Top ten malware families 2006 of Morocco, known as the owner of the online handle “Diabl0”, was sentenced to two years in jail for spreading the Zotob worm.1 Evidence found within some Mytob variants suggests that he was also involved in their creation. With thousands of different variants of Mytob, many of which are hidden within bespoke compression code, it is likely to continue to hit unprotected computer users in 2007. 2 Sophos security threat report 2007 2 Netsky 5 Nyxem On 8 May 2004, the German teenager, Sven Jaschan, was This mass-mailing malware, most commonly known as the arrested in connection with the widespread Netsky and Kama Sutra worm because it uses a variety of pornographic Sasser worm outbreaks. In July 2005, he was sentenced disguises, caused panic for infected computers’ users in to one year and nine months on probation and 30 hours early 2006.6 Its payload was destructive, destroying DOC, community service.2* Despite this sentencing, the Netsky XLS, MDB, MDE, PPT, PPS, ZIP, RAR, PDF, PSD and DMP family, in particular variants Netsky-P and Netsky-D, fi les on the third day of any month. continue to make a signifi cant impact on the charts. 6 Bagle An additional worry is that Netsky-D can run on a default The Bagle family was fi rst seen and protected against in installation of Windows Vista, Microsoft’s recently released January 2004. Despite its maturity, computer users are still operating system.3 Although Vista includes additional being infected by this threat. Several more recent variants security features which will help lock down a computer from spread widely in February 2006: Bagle-CM posed as a attack, this threat again demonstrates the importance of up- message offering free tickets to the Winter Olympic games to-date virus protection. in Turin,7 while Bagle-CO carried the words of love in a fake Valentine greeting. 3 Sober Sober also continues to be a widespread threat. Having fi rst The success of these threats is a result of too many emerged in October 2003, it continues to present itself in computers running today without appropriate protection. Sophos’s top ten lists. Its most widespread variant, Sober-Z, Variants of Bagle will continue to spread via email until fi rst seen in late 2005, sent itself as an email attachment affected computer users install anti-virus against these pretending to be an email from the FBI, CIA or German threats. authorities, and attempted to turn off security software on the user’s computer. It stopped spreading on January 6, 2006 but despite spreading for only a few days at the Microsoft Windows Vista beginning of the year, it still managed to secure the Sober Microsoft launched Windows Vista, its successor for family third place in the list of the most prolifi c malware Windows XP, in November 2006. Vista boasts a number of families of 2006.** security settings, including User Access Control, which allows the user to make choices on what is allowed to run on a case- 4 Zafi by-case basis and offers better protection against malware. Its Another old-timer, Zafi was fi rst seen in April 2004, and Windows Mail email client has a number of default settings spread by harvesting email addresses. The fourth version which can help stop malware from being executed. This is of this code, Zafi -D, is the most widespread of this family.5 good news for computer users. Having an operating system Posing as a Christmas greeting, it used social engineering that can offer better protection against threats will certainly techniques to fool users into launching the attachment. At compliment their security policy. its height, it accounted for 1 in every 10 emails travelling However, it is important that users do not rely solely on the across the internet and claimed number one position in the security improvements in Windows Vista to protect their 2005 virus chart. systems from malware attacks. Sophos tested Microsoft Vista in its default settings and found that three high profi le and widespread email-aware worms would run on Vista: Stratio-Zip, Netsky-D and MyDoom-O. These three variants represented almost 40% of all the threats that were circulating during the month of November 2006. * Two years ago, in a blaze of publicity, Jaschan was hired by a German security Microsoft has an additional challenge to face in the coming fi rm, sending out a dangerous message that virus writers might be able to gain year. With Microsoft comfortably retaining the largest portion hasty employment in the industry despite their malicious behavior. of market share in the operating system business, they will continue to be targeted by malware authors searching for **In an odd twist, an unnamed 20-year-old German man, who had a number vulnerabilities in Vista code. Although Microsoft has made of pornographic pictures of children on his computer, turned himself in to the great improvements in issuing patches for known security authorities, believing a message sent by Sober-Z which claimed he was being holes in the code, exploits are regularly used in malware to investigated by Germany’s Federal Crime Offi ce (known as the BKA) for visiting bypass security on computers. illegal websites4. 3 Sophos security threat report 2007 7 MyDoom 10 Dref The MyDoom family of worms has been widespread for First seen in mid-2005, early versions of Dref spread via a number of years.