WORM_CRIDEX.KG
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
TECHNICAL DETAILS
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:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It drops and executes the following files:
- %User Temp%\exp{number}.tmp.bat - used to delete the initially executed copy
(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It creates the following folders:
- %Application Data%\{random folder name}
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
CurrentVersion\Run
KB{random number}.exe = "%Application Data%\KB{random number}.exe"
Other System Modifications
This worm adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\{random key 2}
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\{random key 1}
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
GlobalUserOffline = "0"
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}3.216.107:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}3.234.138:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}7.17.180:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.219.226:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}7.29.136:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.5.195:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}9.55.163:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.23.100:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}4.74.5:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.18.120:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.129.95:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}66.2:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.130.98:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.135.227:8080/jsbqmCA/hCpyb/Cnw/ED/
- http://{BLOCKED}.30.185:8080/jsbqmCA/hCpyb/Cnw/ED/
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Scan your computer with your Trend Micro product and note files detected as WORM_CRIDEX.KG
Step 3
Restart in Safe Mode
Step 4
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\Internet Settings
- GlobalUserOffline = "0"
- GlobalUserOffline = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\CurrentVersion\Run
- KB{random number}.exe = "%Application Data%\KB{random number}.exe"
- KB{random number}.exe = "%Application Data%\KB{random number}.exe"
Step 5
The following created registry key(s) cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present keys with a backup of the system registry. Note that the said key(s) do not have to be deleted since it won't be harmful to the system:
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT
- {random key 1}
- {random key 1}
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT
- {random key 2}
- {random key 2}
Step 6
Search and delete this file
- %Application Data%\KB{random number}.exe
Step 7
Search and delete these folders
- %Application Data%\{random folder name}
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_CRIDEX.KG. 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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