ALIASES:

Trojan:Win32/Hioles.A (Microsoft); Trojan.FakeAV (Symantec); Trojan-Dropper.Win32.Mudrop.pmp (Kaspersky); Trojan.Win32.Generic!SB.0 (Sunbelt)

 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: 19,968 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 01 Jul 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.

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\SecurityProviders
SecurityProviders = "msapsspc.dll, schannel.dll, digest.dll, msnsspc.dll, msnulxjx.dll"

(Note: The default value data of the said registry entry is msapsspc.dll, schannel.dll, digest.dll, msnsspc.dll.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\SecurityProviders
SecurityProviders = "{random characters}"

(Note: The default value data of the said registry entry is msapsspc.dll, schannel.dll, digest.dll, msnsspc.dll.)

Dropping Routine

This Trojan drops the following files:

  • %System%\msnulxjx.dll
  • %User Profile%\APPLIC~1\nulxjxeo.dll
  • %Temp%\~61a3e02e.tmp
  • %Temp%\~61a3e07c.tmp

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

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

Restore this modified 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_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SecurityProviders
    • From: SecurityProviders = "msapsspc.dll, schannel.dll, digest.dll, msnsspc.dll, msnulxjx.dll"
      To: SecurityProviders = ""msapsspc.dll, schannel.dll, digest.dll, msnsspc.dll""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SecurityProviders
    • From: SecurityProviders = "{random characters}"
      To: SecurityProviders = ""msapsspc.dll, schannel.dll, digest.dll, msnsspc.dll""

Step 3

Search and delete these files

[ 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%\msnulxjx.dll
  • %User Profile%\APPLIC~1\nulxjxeo.dll
  • %Temp%\~61a3e02e.tmp
  • %Temp%\~61a3e07c.tmp

Step 4

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