Email-Worm:W32/MyDoom.Q

The worm's file is a PE executable 21504 bytes long packed with UPX file compressor. The unpacked worm's size is about 62 kilobytes.

System Infection

After the worm's file is run, it opens Notepad application. Then the worm copies itself as WINLIBS.EXE file to Windows System directory and creates a startup key for the copied file in Windows Registry:

• [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run] "winlibs.exe" = "%WinSysDir%\winlibs.exe"

where %WinSysDir% represents Windows System folder. As a result, the worm's file is started every time Windows starts.

Additionally the worm creates the following Registry key:

• [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\winlibs]

The worm creates a mutex named 'NorthernLightMixed'.

Spreading in emails

The worm spreads in emails. Before spreading it collects email addresses from an infected computer. The worm reads Windows Address Book file, reads files in Temporary Internet Files folders and Windows System folder. Files with the following extensions are checked:

• txt
• dhtm
• msg
• htm
• xml
• eml
• html
• sht
• shtm
• shtml
• jse
• jsp
• js
• php
• cfg
• asp
• ods
• mmf
• dbx
• tbb
• adb
• pl
• wab

Additionally the worm can connect to 'email.people.yahoo.com' server and tries to search for victims' email addresses there.

The worm doesn't send itself to email addresses that contain any of the following substrings:

• .edu
• Bug
• ugs
• bug
• upport
• ICROSOFT
• icrosoft
• oot
• dmin
• ymant
• avp
• ecur
• @MM
• ebmast
• help
• opho
• inpris
• omain
• senet
• panda
• 32.
• @mm
• msn
• inux
• umit
• nfo
• irus
• buse
• orton
• cafee
• spam
• Spam
• SPAM
• ntivi
• eport
• user
• inzip
• inrar
• rend
• pdate
• USER
• ating
• ample
• ists
• persk
• ccoun
• ompu
• msdn
• YOU
• you
• oogle
• arsoft
• otmail
• sarc
• soft
• ware
• .gov
• .mil
• cribe
• list
• eturn
• omment
• Sale
• sale
• CRIBE
• gmail
• ruslis
• ibm
• win
• !

The worm spreads in emails with different subject and body texts and with different attachment names. The subject line is selected from the following variants:

• SN: New secure mail
• Secure delivery
• failed transaction
• Re: hello (Securemail)
• Re: Extended Mail
• Delivery Status (Secure)
• Re: Server Reply
• SN: Server Status

The message body can contain user name, domain name and the following text strings:

• Automatically Secure Delivery: for
• Mail Delivery Server System: for
• Extended secure mail message available at:
• Secure Mail Server Notification: for
• New mail secure method implement: for
• New policy requested by mail server to returned mail as a secure compiled attachment (Zip).
• Now a new message is available as secure Zip file format. Due to new policies on clients.
• This message is available as a secure Zip file format due to a new security policy.
• For security measures this message has been packed as Zip format. This is a newly added security feature.
• New policy recommends to enclose all messages as Zip format. Your message is available in this server notice.
• You have received a message that implements secure delivery technology. Message available as a secure Zip file.
• This message is an automatically server notice from Administration at
• Server Notice: New security feature added. MSG:ID: 455sec86
• from
• New feature added for security reasons from
• Automatically server notice:,
• Server reply from
• New service policy for security added from

The attachment name is selected from the following variants:

• mail
• message
• attachment
• transcript
• text
• document
• file
• readme

The attachment extension is selected from these variants:

• .exe
• -txt.exe
• -htm.exe
• -txt.scr

Also the worm can send itself inside a ZIP archive.

The worm fakes the sender's email address. It uses the following user names for the fake email address:

• mike@
• jennifer@
• david@
• linda@
• susan@
• nancy@
• pamela@
• eric@
• kevin@
• mary@
• jessica@
• patricia@
• barbara@
• karen@
• sarah@
• robert@
• john@
• daniel@
• jason@
• joe@

Payload

In the very beginning of its execution the worm creates a thread that enumerates processes and terminates the ones that have the following substrings in their names:

• uba
• mc
• Mc
• av
• AV
• cc
• Sym
• nv
• can
• scn
• java
• xp.exe
• ecur
• nti
• erve
• sss
• iru
• ort
• SkyNet
• KV