WORM_STRAT.MJ

This worm arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It may also compose messages that can be part of its spamming routine.

It executes downloaded files whose malicious routines are exhibited by the affected system. As of this writing, the said sites are inaccessible.

Arrival Details

This worm arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This worm drops the following files:

• %Windows%\tserv.exe - also detected as WORM_STRAT.MJ
• %System%\MSJI449C14B7.DLL - also detected as WORM_STRAT.MJ
• %System%\CMUT449C14B7.DLL - also detected as WORM_STRAT.MJ
• %System%\HPZL449C14B7.EXE - also detected as WORM_STRAT.MJ
• %Windows%\tserv.dll - also detected as WORM_STRAT.MJ
• %System%\e1.dll - also detected as WORM_STRAT.MJ
• %Windows%\tserv.wax - contains e-mail addresses obtained from infected machine
• %Windows%\tserv.dat - non-malicious
• %Windows%\tserv.z - non-malicious
• {Malware Path}\{random number}.tmp - Garbage text opened by notepad to deceive the victim.

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It injects codes into the following process(es):

• nod32krn
• avginet
• avgupsvc
• kavsvc
• upgrader
• drwebupw
• spiderml
• autodown
• kav
• mcupdate
• tbmon
• wuauclt
• wuauclt1
• wupdmgr

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
tserv = "%Windows%\tserv.exe s"

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "msji449c14b7.dll e1.dll"

(Note: The default value data of the said registry entry is {blank}.)

Propagation

This worm gathers target email addresses from files with the following extensions:

• adb
• asp
• cfg
• cgi
• dbx
• eml
• htm
• jsp
• mbx
• mdx
• mht
• mmf
• msg
• nch
• ods
• php
• sht
• stm
• tbb
• txt
• uin
• wab
• wsh
• xml

It may also compose messages that can be part of its spamming routine.

Download Routine

This worm connects to the following website(s) to download and execute a malicious file:

• http://www4.{BLOCKED}njerinkas.com/chr/wtb/lt.exe

It saves the files it downloads using the following names:

• %Temp%\~{random number}.tmp

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

It executes downloaded files :

• %Temp%\~{random number}.tmp - contains massmailing routine

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

As of this writing, the said sites are inaccessible.

Information Theft

This worm gathers the following data:

• Operating System Type
• Operating System Version

Stolen Information

This worm sends the gathered information via HTTP POST to the following URL:

• www3.{BLOCKED}njerinkas.com/cgi-bin/pr.cgi

NOTES:
The worm deletes the downloaded file after execution.