TROJ_DROPPR.FSS

October 12, 2012
 ALIASES:

VirTool:Win32/DelfInject.gen!X (Microsoft); Generic Downloader.il (McAfee); Trojan.Gen.2 (Symantec); Trojan-Dropper.Win32.Clons.pwe (Kaspersky); Trojan.Win32.Packer.NTkrnl0.1 (ep) (Sunbelt); Trojan-Spy:W32/Banker.JGT (FSecure)

 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:

431,617 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Apr 2012

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 Root%\ProgramData\OhxxhbB\XsbhkeL\NtfwioH.exe

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

It creates the following folders:

  • %System Root%\ProgramData
  • %System Root%\ProgramData\OhxxhbB
  • %System Root%\ProgramData\OhxxhbB\PupsvcX
  • %System Root%\ProgramData\OhxxhbB\XsbhkeL
  • %System Root%\ProgramData\OhxxhbB\RwaqgnM

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

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
NtfwioH = "%System Root%\ProgramData\OhxxhbB\XsbhkeL\NtfwioH.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
AmgyGHbJ

HKEY_CURRENT_USER\Software\sistemanet

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
AmgyGHbJ
IddqsSqJ = "{random values}"

HKEY_CURRENT_USER\Software\sistemanet
direct = "jiijehjibjhojaadjaaajaocjaadjigjaoijfhjigjaafjigjibjgijaodjabojabojaodjihjff)"

HKEY_CURRENT_USER\Software\sistemanet
name1 = "jghjaafjaobjaaijaoejaaajgb)"

HKEY_CURRENT_USER\Software\sistemanet
idnome = "jihjaaajaoojaoa)"

HKEY_CURRENT_USER\Software\sistemanet
lugarjpg = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
dir2 = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
dir = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
linka = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
string = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
tbl = "jhdjffjiejffjfhjgg)"

HKEY_CURRENT_USER\Software\sistemanet
aviso = "jaaejaoejaoi)"

HKEY_CURRENT_USER\Software\sistemanet
data = "jeojec)"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\ProgramData\OhxxhbB\RwaqgnM\1

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

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Restart in Safe Mode

[ Learn More ]

Step 3

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\Microsoft
    • AmgyGHbJ
  • In HKEY_CURRENT_USER\Software
    • sistemanet

Step 4

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
    • NtfwioH = "%System Root%\ProgramData\OhxxhbB\XsbhkeL\NtfwioH.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\AmgyGHbJ
    • IddqsSqJ = "{random values}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • direct = "jiijehjibjhojaadjaaajaocjaadjigjaoijfhjigjaafjigjibjgijaodjabojabojaodjihjff)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • name1 = "jghjaafjaobjaaijaoejaaajgb)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • idnome = "jihjaaajaoojaoa)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lugarjpg = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • dir2 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • dir = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • linka = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • string = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • tbl = "jhdjffjiejffjfhjgg)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • aviso = "jaaejaoejaoi)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • data = "jeojec)"

Step 5

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 Root%\ProgramData\OhxxhbB\RwaqgnM\1

Step 6

Search and delete these folders

[ 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%\ProgramData
  • %System Root%\ProgramData\OhxxhbB
  • %System Root%\ProgramData\OhxxhbB\PupsvcX
  • %System Root%\ProgramData\OhxxhbB\XsbhkeL
  • %System Root%\ProgramData\OhxxhbB\RwaqgnM

Step 7

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