WORM_DOWNAD.DM
Trojan:Win32/Sisron (Microsoft); Ransom!dy (McAfee); Trojan.Malcol (Symantec); Trojan-Ransom.Win32.PornoBlocker.aakk (Kaspersky); FraudTool.Win32.AVSoft (v) (Sunbelt); Gen:Variant.Kazy.26530 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
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.
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.
Autostart Technique
This worm modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
SHELL = "explorer.exe, svdhalp.exe"
(Note: The default value data of the said registry entry is Explorer.exe.)
Dropping Routine
This worm drops the following files:
- %Windows%\syskey2i.drv
- %System%\svdhalp.exe
- %System%\svdhalp.exe.ini
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
This report is generated via an automated analysis system.
SOLUTION
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
Identify and delete files detected as WORM_DOWNAD.DM using either the Startup Disk or Recovery Console
Step 3
Restore this modified 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 NT\CurrentVersion\Winlogon
- From: SHELL = "explorer.exe, svdhalp.exe"
To: SHELL = ""Explorer.exe""
- From: SHELL = "explorer.exe, svdhalp.exe"
Step 4
Search and delete these files
- %Windows%\syskey2i.drv
- %System%\svdhalp.exe
- %System%\svdhalp.exe.ini
Step 5
Scan your computer with your Trend Micro product to delete files detected as WORM_DOWNAD.DM. 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.
Did this description help? Tell us how we did.