TROJ_NOSRAWEC.AD

June 18, 2013
 Analysis by: Anthony Joe Melgarejo
 ALIASES:

Generic Downloader.pk (McAfee), Win.Trojan.Downloader-16549 (ClamAV), TrojanDownloader.Genome (VBA32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan may arrive bundled with malware packages as a malware component. 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 executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

2,048 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

14 Jun 2013

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Download Routine

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

  • http://{BLOCKED}.{BLOCKED}.252.125

It saves the files it downloads using the following names:

  • {current malware directory}\test.exe

Trend Micro detects the dowloaded file as:

  • BKDR_NOSRAWEC.AD

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

NOTES:

The URL it accesses is a private IP address. Therefore, it intends to download the file from a host in the Local Area Network (LAN).

This file may have been created for testing purposes or the said IP address in its LAN may have been compromised. This is the downloader component created by HKTL_PANRAT.

  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

Remove malware/grayware files dropped/downloaded by TROJ_NOSRAWEC.AD

    • BKDR_NOSRAWEC.AD

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_NOSRAWEC.AD. 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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