Modified by: Rhena Inocencio
ALIASES:

Trojan:Win32/ServStart.gen!B (Microsoft), Generic Dropper!1yp (McAfee), Trojan.Gen.2 (Symantec), Trojan-Dropper.Win32.XoredBinary.b (v) (Sunbelt), W32/RENOS.SM!tr (Fortinet)

 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • 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.

It modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size: 98,304 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 04 Apr 2008

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:

  • %Program Files%\Windows Media Player\comine.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

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
Windows = "%Program Files%\Windows Media Player\comine.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CLASSES_ROOT\yali
(Default) = "daohang"

HKEY_CLASSES_ROOT\yali
id = "1"

HKEY_CLASSES_ROOT\yali
mac = "{mac address}"

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}code.com/tj/g.asp?id=1&mac={mac address}

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 5.200.05
FIRST VSAPI PATTERN DATE: 04 Apr 2008
VSAPI OPR PATTERN File: 5.201.00
VSAPI OPR PATTERN Date: 05 Apr 2008

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

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry value

[ Learn More ]

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
    • Windows = "%Program Files%\Windows Media Player\comine.exe"

Step 4

Delete this registry key

[ Learn More ]

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_CLASSES_ROOT
    • yali

Step 5

Reset Internet security settings

[ Learn More ]

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_RENOS.SM. 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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