Alureon

Alureon is a trojan and bootkit which is designed, amongst other things, to steal data by intercepting a system's network traffic and searching it for usernames, passwords and credit card data.^[1] Following a series of customer complaints, Microsoft determined that Alureon was the cause of a series of BSoD problems on some 32-bit Microsoft Windows systems which were triggered when some assumptions made by the malware author(s) were broken by Patch Tuesday update MS10-015.^[2][3]

According to research by Microsoft, Alureon was the second most active botnet in the second quarter of 2010.^[4]

Description

The Alureon rootkit was first seen in 2006.^{[citation needed]} PCs usually get infected by manually downloading and installing Trojan software, and has been seen bundled with the rogue security software Security Essentials 2010.^[5] When the dropper is executed, it first hijacks the print spooler service (spoolsv.exe) to write a filesystem at the end of the disk; it then infects low level system drivers such as those responsible for PATA operations (atapi.sys) to implement its rootkit. While Alureon has also been known to redirect search engines to commit click fraud, Google has taken steps to mitigate that for their users by detecting it and warning the user.^[6] Once installed, it blocks access to Windows Update and attempts to disable some anti-virus products.

The malware drew considerable public attention when a software bug in its code caused some 32-bit Windows systems to crash upon installation of security update MS10-015.^[7] The malware was using a hard-coded memory address in the kernel that changed after installation of the hotfix. Microsoft subsequently modified the hotfix to prevent installation if an Alureon infection is present,^[8] while the malware author also fixed the bug in his code.

In November 2010, the press reported that the rootkit has evolved to the point that it is able to bypass the mandatory kernel-mode driver signing requirement of 64-bit editions of Windows 7 by subverting the master boot record,^[9] something that also makes it particularly resistant on all systems to detection and removal by anti-virus software.

Removal

While the rootkit is generally able to hide itself very effectively, circumstancial evidence of the infection may be found by examining network traffic and outbound connections (Netstat). The "FixMbr" command of the Windows Recovery Console and manual replacement of atapi.sys may be required before some anti-virus tools are able to find and clean an infection.

References

External links

• TDSSKiller - Removal tool by Kaspersky
• Virus:Win32/Alureon.A at Microsoft Malware Protection Centre
• Backdoor.Tidserv at Symantec
• Norman TDSS Remover
• TDSS Removal