W32/Mytob-CM is a mass-mailing worm and IRC backdoor Trojan.
W32/Mytob-CM runs continuously in the background, providing a backdoor server which allows a remote intruder to gain access and control over the computer via IRC channels.
W32/Mytob-CM can spread by sending itself as an email ZIP attachment to email addresses it harvests from the infected computer.
Emails sent by the worm have the following characteristics:
Subject line chosen from:
Security measures
Notice: **Last Warning**
*DETECTED* Online User Violation
Your Email Account is Suspended For Security Reasons
Account Alert
Important Notification
*WARNING* Your Email Account Will Be Closed
Email Account Suspension
Notice of account limitation
Message text chosen from:
Once you have completed the form in the attached file , your account records will not be interrupted and will continue as normal.
The original message has been included as an attachment.
We regret to inform you that your account has been suspended due to the violation of our site policy, more info is attached.
We attached some important information regarding your account.
Please read the attached document and follow it's instructions.
<random characters>
The attached file consists of a base name followed by the extentions 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.
When first run W32/Mytob-CM copies itself to <System>\nec.exe.
The following registry entries are created to run nec.exe on startup:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
WINDOWS SYSTEM
nec.exe
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
WINDOWS SYSTEM
nec.exe
W32/Mytob-CM sets the following registry entry, disabling the automatic startup of other software:
HKLM\SYSTEM\CurrentControlSet\Services\SharedAccess
Start
4
W32/Mytob-CM modifies the Windows hosts file in order to block access to the following 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 kaspersky-labs.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.trendmicro.com
127.0.0.1 www.grisoft.com
127.0.0.1 www.microsoft.com
127.0.0.1 microsoft.com
127.0.0.1 www.msn.com
127.0.0.1 www.virustotal.com
127.0.0.1 virustotal.com