TROJ_DLOADE.NF
Backdoor:Win32/Heloag.A, Trojan:Win32/Bumat!rts (Microsoft); Downloader-CAK (McAfee); Trojan Horse (Symantec); Trojan-Downloader.Win32.Agent.dvvm (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
32,768 bytes
EXE
Yes
15 Oct 2012
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.
Autostart Technique
This Trojan 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 %Windows%\csrse.exe "
(Note: The default value data of the said registry entry is Explorer.exe.)
Dropping Routine
This Trojan drops the following files:
- %Windows%\csrse.exe
- %System Root%\SSDT_TOOL.sys
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
This report is generated via an automated analysis system.
SOLUTION
9.200
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 TROJ_DLOADE.NF 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 %Windows%\csrse.exe "
To: Shell = ""Explorer.exe""
- From: Shell = "Explorer.exe %Windows%\csrse.exe "
Step 4
Search and delete these files
- %Windows%\csrse.exe
- %System Root%\SSDT_TOOL.sys
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADE.NF. 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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