WORM_WALEDAC.AT
W32.Waledac.D (Symantec)
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: Yes
In the wild: Yes
OVERVIEW
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It listens on ports. It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
TECHNICAL DETAILS
Arrival Details
This worm 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 and executes the following files:
- %User Profile%\{random}.exe - detected as TROJ_KELIHOS.ACS
(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.)
It drops the following non-malicious files:
- %System%\npf.sys
- %System%\wpcap.dll
- %System%\packet.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
IntelAgent = "{Malware Path and Filename}"
Backdoor Routine
This worm listens on the following ports:
- 80
- 53
It executes the following commands from a remote malicious user:
- Sends out spam e-mails which contain links to TROJ_KELIHOS.ACS. This Trojan, in turn, downloads WORM_WALEDAC.AT
- Steals FTP Credentials
32bit FTP
Bullet Proof FTP
Classic FTP
Core FTP
CuteFTP
FAR Manager FTP
FFFTP
FTP Commander
FTP Commander Deluxe
FTP Commander Pro
FTP Control
FTP Explorer
FTP Navigator
FTPCON
FTPRush
FTPWare
Frigate3 FTP
LeapFTP
SmartFTP
SoftX FTP
TurboFTP - Steals Bitcoins
It connects to the following websites to send and receive information:
- {BLOCKED}o.com
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
Remove malware/grayware files dropped/downloaded by WORM_WALEDAC.AT
- TROJ_KELIHOS.ACS
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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- IntelAgent = "{Malware Path and Filename}"
- IntelAgent = "{Malware Path and Filename}"
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- IntelAgent = "{Malware Path and Filename}"
- IntelAgent = "{Malware Path and Filename}"
Step 6
Search and delete this file
- %System%\npf.sys
- %System%\wpcap.dll
- %System%\packet.dll
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_WALEDAC.AT. 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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