Analysis by: Christopher Daniel So

 ALIASES:

Rootkit.Win32.Korablin.a (Kaspersky)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

It hides files, processes, and/or registry entries.

  TECHNICAL DETAILS

File Size: Varies
File Type: SYS
Memory Resident: Yes
Initial Samples Received Date: 23 Aug 2012
Payload: Modifies system registry, Modifies files

Arrival Details

This Trojan may be dropped by the following malware:

  • WORM_MORCUT.A

Rootkit Capabilities

This Trojan is used by other malware for its rootkit functionalities.

It hides files, processes, and/or registry entries.

NOTES:
It is dropped by WORM_MORCUT.A as %System%\drivers\ndisk.sys.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.344.02
FIRST VSAPI PATTERN DATE: 24 Aug 2012
VSAPI OPR PATTERN File: 9.345.00
VSAPI OPR PATTERN Date: 24 Aug 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 the malware/grayware file that dropped/downloaded RTKT_MORCUT.A

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete this file

[ 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.
  • %System%\drivers\ndisk.sys

Step 5

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