Sophos's anti-virus products include Genotype detection technology, which can proactively protect against new threats without requiring an update. Sophos customers have been protected against W32/Mytob-X (detected as W32/MyDoom-Gen) since version 3.92.
W32/Mytob-X is a mass-mailing worm and backdoor Trojan that targets users of Internet Relay Chat programs.
W32/Mytob-X is capable of spreading through operating system vulnerabilities such as LSASS (MS04-011).
When first run, W32/Mytob-X copies itself to the Windows system folder as WindowsFirewall.exe and creates the following registry entries:
HKCU\Software\Microsoft\OLE
Windows Firewall
WindowsFirewall.exe
HKCU\System\CurrentControlSet\Control\Lsa
Windows Firewall
WindowsFirewall.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Windows Firewall
WindowsFirewall.exe
HKLM\Software\Microsoft\Ole
Windows Firewall
WindowsFirewall.exe
HKLM\System\CurrentControlSet\Control\Lsa
Windows Firewall
WindowsFirewall.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
Windows Firewall
WindowsFirewall.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
Windows Firewall
WindowsFirewall.exe
W32/Mytob-X copies itself to the root folder as:
funny_pic.scr
my_photo2005.scr
see_this!!.scr
and creates the helper file hellmsn.exe (detected by Sophos as W32/Mytob-D) in the same location.
W32/Mytob-X arrives in an email with the following characteristics:
Subject line:
Error
Status
Server Report
Mail Transaction Failed
Mail Delivery System
hello
Good day
<random characters>
Message text:
Here are your banks documents.
The original message was included as an attachment.
The message cannot be represented in 7-bit ASCII encoding and has been sent as a binary attachment.
The message contains Unicode characters and has been sent as a binary attachment.
Mail transaction failed. Partial message is available.
The attached file consists of a base name followed by the extentions BAT, CMD, PIF, SCR, EXE or ZIP. The worm may optionally create double extensions where the first extension is DOC, TXT or HTM and the final extension is PIF, SCR, EXE or ZIP.
W32/Mytob-X also appends the following to the HOSTS file to deny access to security related websites:
127.0.0.1 www.symantec.com
127.0.0.1 securityresponse.symantec.com
127.0.0.1 symantec.com
127.0.0.1 www.sophos.com
127.0.0.1 sophos.com
127.0.0.1 www.mcafee.com
127.0.0.1 mcafee.com
127.0.0.1 liveupdate.symantecliveupdate.com
127.0.0.1 www.viruslist.com
127.0.0.1 viruslist.com
127.0.0.1 viruslist.com
127.0.0.1 f-secure.com
127.0.0.1 www.f-secure.com
127.0.0.1 kaspersky.com
127.0.0.1 www.avp.com
127.0.0.1 www.kaspersky.com
127.0.0.1 avp.com
127.0.0.1 www.networkassociates.com
127.0.0.1 networkassociates.com
127.0.0.1 www.ca.com
127.0.0.1 ca.com
127.0.0.1 mast.mcafee.com
127.0.0.1 my-etrust.com
127.0.0.1 www.my-etrust.com
127.0.0.1 download.mcafee.com
127.0.0.1 dispatch.mcafee.com
127.0.0.1 secure.nai.com
127.0.0.1 nai.com
127.0.0.1 www.nai.com
127.0.0.1 update.symantec.com
127.0.0.1 updates.symantec.com
127.0.0.1 us.mcafee.com
127.0.0.1 liveupdate.symantec.com
127.0.0.1 customer.symantec.com
127.0.0.1 rads.mcafee.com
127.0.0.1 trendmicro.com
127.0.0.1 www.microsoft.com
127.0.0.1 www.trendmicro.com