PE_CORELINK.A
Virus:Win32/Almanahe.A (Microsoft); PWS-Zbot.gen.cn (McAfee); W32.Virut.CF (Symantec); Virus.Win32.Alman.a (Kaspersky); Virus.Win32.Virut.ce (v) (Sunbelt); Win32.Almam.A (FSecure)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: File infector
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
163,840 bytes
EXE
01 Oct 2011
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 creates the following folders:
- %User Profile%\Microsoft\Dr Watson
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Other System Modifications
This file infector deletes the following files:
- %System%\drivers\DKIS6.sys
- %Windows%\AppPatch\apphelps.dll.update
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DrWatson
NumberOfCrashes = 1
(Note: The default value data of the said registry entry is 0.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
PCHealth\ErrorReporting\DW
Dropping Routine
This file infector drops the following files:
- %Windows%\linkinfo.dll
- %System%\drivers\DKIS6.sys
- %System%\drivers\RioDrvs.sys
- %User Profile%\Dr Watson\drwtsn32.log
- %User Profile%\Dr Watson\user.dmp
- %Windows%\AppPatch\apphelps.dll.update
- %Windows%\AppPatch\apphelps.dll
(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Other Details
This file infector connects to the following possibly malicious URL:
- http://tj.{BLOCKED}ldwide.com/co.asp?{random characters}
- http://tj.{BLOCKED}ldwide.com/co.asp?action=update&version=0
- http://soft.{BLOCKED}ldwide.com/z.dat
This report is generated via an automated analysis system.
SOLUTION
9.200
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
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DrWatson
- From: NumberOfCrashes=1
To: NumberOfCrashes=0
- From: NumberOfCrashes=1
Step 3
Search and delete this folder
Step 4
Search and delete these files
- %Windows%\linkinfo.dll
- %System%\drivers\DKIS6.sys
- %System%\drivers\RioDrvs.sys
- %User Profile%\Dr Watson\drwtsn32.log
- %User Profile%\Dr Watson\user.dmp
- %Windows%\AppPatch\apphelps.dll.update
- %Windows%\AppPatch\apphelps.dll
Step 5
Scan your computer with your Trend Micro product to clean files detected as PE_CORELINK.A. 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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