TROJ_DOFOIL.JF
TrojanDownloader:Win32/Kuluoz.C (Microsoft), Trojan-Dropper.Win32.Dapato.bncl (Kaspersky), Trojan.Smoaler (Symantec), Downloader.a!cdm (NAI), Troj/Agent-XCQ (Sophos), Trojan.Generic.KDV.679141 (FSecure), Trojan.Win32.Generic!BT (Sunbelt), W32/Trojan3.DWD (Authentium), Trojan.Generic.KDV.679141 (Bitdefender), PUA.Win32.Packer.Upx-28 (Clamav), W32/Dapato.BNCL!tr (Fortinet), W32/Trojan3.DWD (exact) (Fprot), Trojan-Dropper.Win32.Dapato (Ikarus), Win32/TrojanDownloader.Zortob.B trojan (NOD32), Trojan W32/Suspicious_Gen4.APPNT (Norman)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It uses common file icons to trick a user into thinking that the files are legitimate.
It connects to a website to send and receive information.
It deletes itself after execution.
TECHNICAL DETAILS
Arrival Details
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It 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 a copy of itself in the following folders using different file names:
- %Application Data%\{random filename}.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It adds the following processes:
- svchost.exe
It uses common file icons to trick a user into thinking that the files are legitimate.
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random characters} = "%Application Data%\{random file name}.exe"
Backdoor Routine
This Trojan connects to the following websites to send and receive information:
- {BLOCKED}.{BLOCKED}.13.19:80
- {BLOCKED}.{BLOCKED}.13.32:80
- {BLOCKED}.{BLOCKED}.149.230:80
- {BLOCKED}.{BLOCKED}.241.131:80
- {BLOCKED}.{BLOCKED}.246.95:80
- {BLOCKED}.{BLOCKED}.234.37:80
Other Details
This Trojan deletes itself after execution.
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
Restart in Safe Mode
Step 3
Delete the registry entry with an unknown data 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random characters} = "%Application Data%\{random file name}.exe"
- {random characters} = "%Application Data%\{random file name}.exe"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DOFOIL.JF. 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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