TROJ_PAWXNIC.A


 PLATFORM:

Windows

 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:

369,221 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Feb 2016

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 creates the following folders:

  • %System Root%\DOCUME~1
  • %System Root%\DOCUME~1\Wilbert
  • %User Profile%\LOCALS~1

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\
Microsoft\Internet Explorer\Privacy

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
A9753DC515D30D1D048F33765B95C105EB58A403

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "http://{BLOCKED}dates.com/mwhaqF/87U.pac"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "http://{BLOCKED}dates.com/mwhaqF/87U.pac"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
WarnonBadCertRecving = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
ClearBrowsingHistoryOnExit = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanTIF = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
UseAllowList = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\ROOT\Certificates\
A9753DC515D30D1D048F33765B95C105EB58A403
Blob = "{random values}"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Connections
DefaultConnectionSettings = "{random values}"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This Trojan drops the following files:

  • __tmp_rar_sfx_access_check_650156
  • index33.exe
  • label2_ems.gif

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}heck.com/nsb2/SoftCheck.php?{random characters}

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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

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_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\Microsoft\Internet Explorer
    • Privacy
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates
    • A9753DC515D30D1D048F33765B95C105EB58A403

Step 3

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings
    • AutoConfigURL = "http://{BLOCKED}dates.com/mwhaqF/87U.pac"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • AutoConfigURL = "http://{BLOCKED}dates.com/mwhaqF/87U.pac"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • WarnonBadCertRecving = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
    • ClearBrowsingHistoryOnExit = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
    • CleanTIF = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
    • UseAllowList = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\ROOT\Certificates\A9753DC515D30D1D048F33765B95C105EB58A403
    • Blob = "{random values}"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections
    • From: DefaultConnectionSettings = "{random values}"
      To: DefaultConnectionSettings = ""{random values}""

Step 5

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.
  • __tmp_rar_sfx_access_check_650156
  • index33.exe
  • label2_ems.gif

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%\DOCUME~1
  • %System Root%\DOCUME~1\Wilbert
  • %User Profile%\LOCALS~1

Step 7

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