WORM_RJUMP.AI

 Modified by: Arvin Roi Macaraeg

 ALIASES:

Trojan.Win32.Agent.aeim (KASPERSKY), Worm:Win32/RJump.F (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet


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.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

49,242 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Mar 2011

Payload:

Connects to URLs/IPs

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.

Installation

This Worm drops the following files:

  • %Windows%\SVCHOST.INI
  • %System Root%\AutoRun.inf
  • {All Drives}\AutoRun.inf

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It drops and executes the following files:

  • %Windows%\MDM.EXE

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It drops the following copies of itself into the affected system:

  • %System Root%\RavMon.exe
  • {All Drives}\RavMon.exe
  • %Windows%\SVCHOST.EXE

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Autostart Technique

This Worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SVCHOST = "%Windows%\MDM.EXE"

Other System Modifications

This Worm modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

Propagation

The said .INF file contains the following strings:

[AutoRun]
open=RavMon.exe
shell\open=´ò¿ª(&O)
shell\open\Command=RavMon.exe
shell\explore=×ÊÔ´¹ÜÀíÆ÷(&X)
shell\explore\Command="RavMon.exe -e"

Download Routine

This Worm connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}t.cn/task.asp?mac={mac address}

It saves the files it downloads using the following names:

  • %User Temp%{random 4 characters}.tmp

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.850

VSAPI OPR PATTERN File:

5.883.00

VSAPI OPR PATTERN Date:

08 Apr 2009

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

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
    • SVCHOST = "%Windows%\MDM.EXE"

Step 4

Restore this modified 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\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = "0"
      To: CheckedValue = {User Dependent Value}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "2"
      To: Hidden = {User Dependent Value}

Step 5

Search and delete these files

[ Learn More ]
There may be some 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.  
  • %Windows%\SVCHOST.EXE
  • %System Root%\RavMon.exe
  • {All Drives}\RavMon.exe
  • %Windows%\MDM.EXE
  • %Windows%\SVCHOST.INI
  • %User Temp%{random 4 characters}.tmp

Step 6

Search and delete AUTORUN.INF files created by WORM_RJUMP.AI that contain these strings

[ Learn More ]
[AutoRun]
open=RavMon.exe
shell\open=´ò¿ª(&O)
shell\open\Command=RavMon.exe
shell\explore=×ÊÔ´¹ÜÀíÆ÷(&X)
shell\explore\Command=RavMon.exe -e

Step 7

Scan your computer with your Trend Micro product to delete files detected as WORM_RJUMP.AI. 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 the following Trend Micro Support pages for more information:


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