Trojan.BrowserAssistant.PS

Short bio

Trojan.BrowserAssistant.PS is Malwarebytes’ detection name for a Trojan that injects javascript code in targeted browsers (Edge and Firefox). The BrowserAssistant installer is signed by Realistic Media Inc. and aimed at Windows systems.

Symptoms

Users of affected systems may see this entry in their list of installed Programs and Features:

BrowserAssistant installed

and these items in the Windows Startup folder:

startup entries

Type and source of infection

Trojan.BrowserAssistant.PS is a Trojan that allows the threat actor to show advertisements in the affected browsers.
Trojan.BrowserAssistant.PS is installed as part of bundlers.

installing BrowserAssistant

Protection

Malwarebytes protects users from Trojan.BrowserAssistant.PS by using real-time protection.

block BrowserAssistant

Malwarebytes blocks Trojan.BrowserAssistant.PS

Remediation

Malwarebytes can detect and remove Trojan.BrowserAssistant.PS without further user interaction.

  1. Please download Malwarebytes to your desktop.
  2. Double-click mb3-setup-consumer-{version}.exe and follow the prompts to install the program.
  3. Then click Finish.
  4. Once the program has fully updated, select Scan Now on the Dashboard. Or select the Threat Scan from the Scan menu.
  5. If another update of the definitions is available, it will be implemented before the rest of the scanning procedure.
  6. When the scan is complete, make sure that all Threats are selected, and click Remove Selected.
  7. Restart your computer when prompted to do so.

Malwarebytes removal log

A Malwarebytes log of removal will be huge but should contain these entries:

Malwarebytes
www.malwarebytes.com

-Log Details-
Scan Date: 7/25/19
Scan Time: 1:16 PM
Log File: a687e548-aecd-11e9-ad51-00ffdcc6fdfc.json

-Software Information-
Version: 3.7.1.2839
Components Version: 1.0.586
Update Package Version: 1.0.11712
License: Premium

-System Information-
OS: Windows 7 Service Pack 1
CPU: x64
File System: NTFS
User: {computername}\{username}

-Scan Summary-
Scan Type: Threat Scan
Scan Initiated By: Manual
Result: Completed
Objects Scanned: 237392
Threats Detected: 2255
Threats Quarantined: 2255
Time Elapsed: 48 min, 59 sec

-Scan Options-
Memory: Enabled
Startup: Enabled
Filesystem: Enabled
Archives: Enabled
Rootkits: Enabled
Heuristics: Enabled
PUP: Detect
PUM: Detect

-Scan Details-
Process: 0
(No malicious items detected)

Module: 0
(No malicious items detected)

Registry Key: 1
Trojan.BrowserAssistant.Powershell, HKCU\SOFTWARE\REALISTIC MEDIA INC.\Browser Assistant, Quarantined, [3839], [661357],1.0.11712
Registry Value: 1
PUP.Optional.QXSearch, HKCU\SOFTWARE\GOOGLE\CHROME\PREFERENCEMACS\Default\extensions.settings|pidepfbnmnemhcencgnfhhfnfiebdgjk, Quarantined, [352], [676735],1.0.11712

Registry Data: 0
(No malicious items detected)

Data Stream: 0
(No malicious items detected)

Folder: 148
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\node_modules\@cliqz-oss\firefox-client\test, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\extension\js, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\node_modules, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\WebDrivers, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\extension, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\edge\x86, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\engine, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\edge, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\Users\{username}\AppData\Roaming\Browser Assistant\api, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.PS, C:\USERS\{username}\APPDATA\ROAMING\BROWSER ASSISTANT, Quarantined, [3840], [710827],1.0.11712
Trojan.BrowserAssistant.Powershell, C:\USERS\{username}\APPDATA\ROAMING\MICROSOFT\WINDOWS\START MENU\PROGRAMS\STARTUP\UPDATER.LNK, Quarantined, [3839], [652810],1.0.11712

Physical Sector: 0
(No malicious items detected)

WMI: 0
(No malicious items detected)

(end)

Traces/IOCs

You may see these entries in FRST logs:

Startup: C:\Users\{username}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\BrowserAssistant.lnk [2019-07-25]
ShortcutTarget: BrowserAssistant.lnk -> C:\Users\{username}\AppData\Roaming\Browser Assistant\BrowserAssistant.exe (Realistic Media Inc. -> )
Startup: C:\Users\{username}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\updater.lnk [2019-07-25]
ShortcutAndArgument: updater.lnk -> C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe => -noninteractive -ExecutionPolicy bypass -c “try{$w=”$env:APPDATA”+’\Browser Assistant\’;[Reflection.Assembly]::Load([System.IO.File]::ReadAllBytes($w+’Updater.dll’));$i=new-object u.U;$i.R()}catch{}”


C:\Users\{username}\AppData\Roaming\Browser Assistant

Browser Assistant (HKLM-x32\…\{367D5074-5E48-40AF-B009-7D3839DAE5E4}) (Version: 1.21.6922.27430 – Realistic Media Inc.)

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