PERL_DAVKIT.A
Windows 2000, XP, Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
It may also overwrite the following files if they exist:
- C:\mIRC\script.ini
- %Program Files%\mIRC\script.ini
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It restarts the affected system.
TECHNICAL DETAILS
11,046 bytes
Script
No
10 Feb 2005
Compromises system security
Arrival Details
This Trojan 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 Trojan drops the following copies of itself into the affected system:
- %Windows%\csscheat.bat
- %Program Files%\sharex\xxx\xxxlist.bat
- %Program Files%\sharex\crackz\css_xwallhack.bat
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
It creates the following folders:
- %Program Files%\sharex\xxx
- %Program Files%\sharex\crackz
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
vwin = %Windows%\%v%.bat
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
vwin = %Windows%\%v%.bat
It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- C:\Dokumente und Einstellungen\All Users\Startmenü\Programme\Autostart\win.bat
- C:\Documents and Settings\All Users\Start Menu\Programs\Startup\win.bat
Other System Modifications
This Trojan adds the following line(s)/entry(ies) in the WIN.INI file:
- [windows]
- run=%windir%\%v%.bat
- load=%windir%\%v%.bat
File Infection
This Trojan overwrites files with the following extensions:
- .bat
- .txt
- .doc
- .exe
- .ini
- .cfg
Process Termination
This Trojan terminates processes or services that contain any of the following strings if found running in the affected system's memory:
- norton
- av
- fire
- anti
- spy
- bullguard
- PersFw
- KAV
- ZONEALARM
- SAFEWEB
- OUTPOST
- nv
- nav
- F-
- ESAFE
- cle
- BLACKICE
- def
HOSTS File Modification
This Trojan adds the following strings to the Windows HOSTS file:
- 127.0.0.1 www.google.com
- 127.0.0.1 www.google.de
- 127.0.0.1 www.symantec.de
- 127.0.0.1 www.free-av.de
- 127.0.0.1 www.free-av.com
- 127.0.0.1 www.antivir.de
- 127.0.0.1 www.antivir.com
- 127.0.0.1 www.kaspersky.com
- 127.0.0.1 www.kaspersky.de
- 127.0.0.1 www.microsoft.com
- 127.0.0.1 www.microsoft.de
- 127.0.0.1 www.sophos.com
- 127.0.0.1 www.sophos.de
- 127.0.0.1 www.symantec.com
- 127.0.0.1 www.hijackthis.de
- 127.0.0.1 www.spychecker.com
- 127.0.0.1 www.trendmicro.com
- 127.0.0.1 www.trendmicro.de
- 127.0.0.1 www.lavasoftusa.com
- 127.0.0.1 www.yahoo.com
- 127.0.0.1 www.yahoo.de
- 127.0.0.1 www.lycos.com
- 127.0.0.1 www.lycos.de
Other Details
This Trojan restarts the affected system.
It does the following:
- It may also overwrite the following files if they exist:
- C:\mIRC\script.ini
- %Program Files%\mIRC\script.ini
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
SOLUTION
8.900
2.402.00
10 Feb 2005
2/10/2005 12:00:00 AM
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
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\Software\Microsoft\Windows\CurrentVersion\Run
- vwin = %Windows%\%v%.bat
- vwin = %Windows%\%v%.bat
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- vwin = %Windows%\%v%.bat
- vwin = %Windows%\%v%.bat
Step 3
Search and delete these folders
Step 4
Remove these strings added by the malware/grayware/spyware in the HOSTS file
Step 5
Scan your computer with your Trend Micro product to delete files detected as PERL_DAVKIT.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.
Step 6
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
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