TROJ_MDROPPR.RC

October 09, 2012
 Analysis by: Abraham Latimer Camba
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Spammed via email, Downloaded from the Internet

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 does not have any propagation routine.

It does not have any backdoor routine.

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size:

459,500 bytes

File Type:

DOC

Initial Samples Received Date:

18 Feb 2012

Payload:

Drops files

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 the following non-malicious files:

  • %User Profile%\Local Settings\iros2012.doc
  • %User Profile%\Local Settings\log1.txt

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Local Settings\fabc.scr - detected by Trend Micro as TROJ_DROPPR.RK
  • %User Profile%\Local Settings\abc.scr - detected by Trend Micro as BKDR_FYNLOS.SM

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It takes advantage of the following software vulnerabilities to drop malicious files:

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

It opens the dropped file %User Profile%\Local Settings\iros2012.doc in Microsoft Word to hide its malicious routines.

It does not have rootkit capabilities.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.932.06

FIRST VSAPI PATTERN DATE:

24 Apr 2012

VSAPI OPR PATTERN File:

8.933.00

VSAPI OPR PATTERN Date:

24 Apr 2012

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

Remove malware files dropped/downloaded by TROJ_MDROPPR.RC

    • TROJ_DROPPR.RK
    • BKDR_FYNLOS.SM

Step 3

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Profile%\Local Settings\iros2012.doc
  • %User Profile%\Local Settings\log1.txt

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROPPR.RC. 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.

Step 5

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


Did this description help? Tell us how we did.