PLATFORM:

Windows 2000, Windows XP, Windows 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 disables Task Manager, Registry Editor, and Folder Options.

  TECHNICAL DETAILS

File Size: 151,552 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 May 2013

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 creates the following folders:

  • %Application Data%\6abce574-4afc-42c5-8ab9-5739a84d8a8bad

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

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
Adobe CSS5.1 Manager = "{random characters}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
Adobe CSS5.1 Manager = "{random characters}"

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following registry keys:

HKEY_CURRENT_USER\SOFTWARE\Adobe\
CSXS.2.5

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Adobe\
CSXS.2.5
bProofingSpace = "{random values}"

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
abceafccabadabad = "{random characters}"

Dropping Routine

This Trojan drops the following files:

  • %Windows%\Tasks\{70BEDB74-F0DF-4911-A4D0-A6DC1902C429}.job

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}oft.com

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.

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_CURRENT_USER\SOFTWARE\Adobe
    • CSXS.2.5
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • Run
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
    • RunOnce

Step 5

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Adobe CSS5.1 Manager = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • Adobe CSS5.1 Manager = "{random characters}"
  • In HKEY_CURRENT_USER\Software\Adobe\CSXS.2.5
    • bProofingSpace = "{random values}"

Step 6

Search and delete this file

[ 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%\Tasks\{70BEDB74-F0DF-4911-A4D0-A6DC1902C429}.job

Step 7

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\6abce574-4afc-42c5-8ab9-5739a84d8a8bad

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_REDYMS.SS. 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 9

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log


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