PE_VIRUX.O
Windows 2000, Windows XP, Windows Server 2003
Threat Type: File infector
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This file infector connects to certain IRC server(s).
This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It prevents users from visiting antivirus-related websites that contain specific strings.
TECHNICAL DETAILS
Arrival Details
This file infector 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 file infector injects codes into the following process(es):
- winlogon.exe
Other System Modifications
This file infector adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
\??\%System%\winlogon.exe = \??\%System\winlogon.exe:*:enabled:@shell32.dll,-1
File Infection
This file infector infects the following file types:
- EXE
- SCR
It avoids infecting files that contain the following strings in their names:
- OTSP
- WC32
- WCUN
- WINC
It avoids infecting the following files:
- .DLL files
- PE Files with _win section name
- Files with infection marker
Backdoor Routine
This file infector connects to any of the following IRC server(s):
- {BLOCKED}cgalaxy.pl
- {BLOCKED}ns.pl
Other Details
This file infector prevents users from visiting antivirus-related websites that contain the following strings:
- ahnlab
- arcabit
- avast
- avira
- castlecops
- centralcommand
- clamav
- comodo
- computerassociates
- cpsecure
- defender
- drweb
- emsisoft
- esafe
- eset
- etrust
- ewido
- f-prot
- f-secure
- fortinet
- gdata
- grisoft
- hacksoft
- hauri
- ikarus
- jotti
- k7computing
- kaspersky
- malware
- mcafee
- microsoft
- networkassociates
- nod32
- norman
- norton
- panda
- pctools
- prevx
- quickheal
- rising
- rootkit
- securecomputing
- sophos
- spamhaus
- spyware
- sunbelt
- symantec
- threatexpert
- trendmicro
- virus
- wilderssecurity
- windowsupdate
NOTES:
It hooks the following APIs so that when these APIs are called, the virus code is executed thus infecting files:
- NtCreateFile
- NtOpenFile
- NtCreateProcess
- NtCreateProcessEx
- NtQueryInformationProcess
It returns execution to the host file's original code after execution.
It connects to the mentioned servers using eight randomly-generated character for its NICK and one randomly-generated character for its USER. Once connected to the IRC server, it joins a certain channel to receive and execute commands on the affected system.
As of this writing, no reply has been received from the servers.
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 PE_VIRUX.O
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- \??\%System%\winlogon.exe = \??\%System\winlogon.exe:*:enabled:@shell32.dll,-1
- \??\%System%\winlogon.exe = \??\%System\winlogon.exe:*:enabled:@shell32.dll,-1
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_VIRUX.O. 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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