arrow_back
search
close

TROJ_SMALL.NHJ

March 13, 2013
 ALIASES:

TrojanDownloader:Win32/Small.gen!AZ (Microsoft); Generic Downloader.x!g2r (McAfee); Trojan.Dropper (Symantec); Trojan-Downloader.Win32.Small (Sunbelt); Trojan horse Downloader.Generic12.BHAB (AVG)

 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.

  TECHNICAL DETAILS

File Size:

113,664 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

13 Mar 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 drops the following copies of itself into the affected system:

  • %System%\remotemgr.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It creates the following folders:

  • %System Root%\RECYCLER

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\2012³âµµ Á¤±âÀÌ»çȸ °³ÃÖ °øÁö-AIRRCS.HWP
  • %User Temp%\38000.tmp
  • %Temp%\45671.tmp

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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 and 7.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}sh.com/upload/design/12754_main_top_l_bg.gif
  • http://{BLOCKED}ol.com/bbs/files/fqna/sky-12.gif

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

Search and delete these components

[ Learn More ]
There may be some components 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 Root%\2012³âµµ Á¤±âÀÌ»çȸ °³ÃÖ °øÁö-AIRRCS.HWP
  • %User Temp%\38000.tmp
  • %Temp%\45671.tmp

Step 3

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.
  • %System Root%\RECYCLER

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_SMALL.NHJ. 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.


Did this description help? Tell us how we did.