ADW_DNSUNLOCKER.GB

August 31, 2017
 Analysis by: Byron Jon Gelera
 ALIASES:

Adware.DNSUnlocker (Symantec); not-a-virus:HEUR:AdWare.Win32.DNSUnlocker.gen (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Adware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be manually installed by a user.

  TECHNICAL DETAILS

File Size:

494,592 bytes

File Type:

DLL

Memory Resident:

No

Initial Samples Received Date:

10 Aug 2017

Arrival Details

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

It may be manually installed by a user.

Installation

This Adware drops the following files:

  • %Windows%\Tasks\{GUID}.job (for Windows XP and below)

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Autostart Technique

The scheduled task executes the malware every:

  • Daily

Other System Modifications

This Adware adds the following registry entries:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
{Random characters}
{0/1} = "{Random}"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
{Random numbers}
0 = "4"

Other Details

This Adware connects to the following possibly malicious URL:

  • http://{BLOCKED}roffi.com/u

  SOLUTION

Minimum Scan Engine:

9.850

SSAPI PATTERN File:

1.865.00

SSAPI PATTERN Date:

17 Aug 2017

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

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\Uninstall\{Random numbers}
    • 0 = "4"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall\{Random characters}
    • {0/1} = {Random}

Step 4

Search and delete this file

[ Learn More ]
There may be some 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.
  • %Windows%\Tasks\{GUID}.job

Step 5

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