WORM_CRIDEX.V
Worm:Win32/Cridex.E (Microsoft), Trojan-Dropper.Win32.Dapato.blhj (Kaspersky), W32.Cridex (Symantec), Troj/Bredo-AAD (Sophos), Trojan.Win32.Generic.pak!cobra (Sunbelt), W32/Kryptik.AB!t (Fortinet)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It uses icons similar to those of legitimate applications to entice a user to click them.
It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
It connects to certain websites to send and receive information. It restarts the affected system.
TECHNICAL DETAILS
89,088 bytes
Yes
06 Jul 2012
Arrival Details
This worm arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This worm drops the following copies of itself into the affected system:
- %Application Data%\KB{random number}.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It drops the following file(s)/component(s):
- %User Temp%\expA.tmp - detected as WORM_CRIDEX.V
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
It injects threads into the following normal process(es):
- csrss.exe
- svchost.exe
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
KB{random numbers} = "%Application Data%\KB{random numbers}.exe"
Propagation
This worm uses icons similar to those of legitimate applications to entice a user to click them.
Dropping Routine
This worm executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
Other Details
This worm connects to the following website to send and receive information:
- {BLOCKED}.{BLOCKED}.189.124
- {BLOCKED}.{BLOCKED}.147.35:8080
- {BLOCKED}.{BLOCKED}.23.100:8080
- {BLOCKED}.{BLOCKED}.250.173
- {BLOCKED}.{BLOCKED}-189-212-dynip.{BLOCKED}bel.de:8080
- {BLOCKED}.{BLOCKED}.5.140:8080
- {BLOCKED}.{BLOCKED}.164.18
- {BLOCKED}.{BLOCKED}.179.185
- abs-static-{BLOCKED}.{BLOCKED}.68.58.{BLOCKED}l.co.in:8080
- arquivo.{BLOCKED}r.com.br:8080
- host-134-23.{BLOCKED}c.eu:8080
- {BLOCKED}andmore.com:8080
It restarts the affected system.
SOLUTION
9.200
9.242.03
07 Jul 2012
9.243.00
08 Jul 2012
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Scan your computer with your Trend Micro product and note files detected as WORM_CRIDEX.V
Step 3
Restart in Safe Mode
Step 4
Search and delete files detected as WORM_CRIDEX.V
Step 5
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- KB{random numbers} = %Application Data%\KB{random numbers}.exe
- KB{random numbers} = %Application Data%\KB{random numbers}.exe
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_CRIDEX.V. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
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