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What is PDFSearchHQ?

The Malwarebytes research team has determined that PDFSearchHQ is a search hijacker. These so-called "hijackers" manipulate your browser(s), for example to change your startpage or searchscopes, so that the affected browser visits their site or one of their choice.
This particular one is a search hijacker and uses web push notifications. It also adds advertisements to your search results in the form of recommended searches.


How do I know if my computer is affected by PDFSearchHQ?

You may see this entry in your list of installed Chrome extensions:


and these warnings during install:




and these changed settings:



How did PDFSearchHQ get on my computer?

Browser hijackers use different methods for distributing themselves. This particular one was downloaded from the webstore:


after a redirect from their website:


How do I remove PDFSearchHQ?

Our program Malwarebytes can detect and remove this potentially unwanted program.

  • Please download Malwarebytes for Windows to your desktop.
  • Double-click MBSetup.exe and follow the prompts to install the program.
  • When your Malwarebytes for Windows installation completes, the program opens to the Welcome to Malwarebytes screen.
  • Click on the Get started button.
  • Click Scan to start a Threat Scan.
  • When the scan is finished click Quarantine to remove the found threats.
  • Reboot the system if prompted to complete the removal process.

Is there anything else I need to do to get rid of PDFSearchHQ?

  • No, Malwarebytes removes PDFSearchHQ completely.
  • If you have allowed the notifications you can read here how to disable them.

How would the full version of Malwarebytes help protect me?

We hope our application and this guide have helped you eradicate this hijacker.

As you can see below Malwarebytes Browser Guard, and the full version of Malwarebytes would have protected you against the PDFSearchHQ hijacker. It would have blocked their website, giving you a chance to stop it before it became too late.


Technical details for experts

Possible signs in FRST logs:

CHR Notifications: Default -> hxxps://install.pdfsearchhq.com
CHR DefaultSearchURL: Default -> hxxps://feed.pdfsearchhq.com/?q={searchTerms}&publisher=pdfsearchhq&barcodeid=586490000000000
CHR DefaultSearchKeyword: Default -> PDFSearchHQ
CHR DefaultSuggestURL: Default -> hxxps://api.pdfsearchhq.com/suggest/get?q={searchTerms}
CHR Extension: (PDFSearchHQ) - C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Extensions\hbfcbidlcbnolaphegpcpippkdpckihf [2021-01-06]

Alterations made by the installer:

File system details [View: All details] (Selection)
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Extensions\hbfcbidlcbnolaphegpcpippkdpckihf\1.1.0_0
       Adds the file manifest.json"="1/6/2021 9:13 AM, 2072 bytes, A
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Extensions\hbfcbidlcbnolaphegpcpippkdpckihf\1.1.0_0\_metadata
       Adds the file computed_hashes.json"="1/6/2021 9:13 AM, 6725 bytes, A
       Adds the file verified_contents.json"="11/16/2020 11:11 AM, 2049 bytes, A
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Extensions\hbfcbidlcbnolaphegpcpippkdpckihf\1.1.0_0\images
       Adds the file logo-white-text.png"="11/16/2020 11:11 AM, 0 bytes, A
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Extensions\hbfcbidlcbnolaphegpcpippkdpckihf\1.1.0_0\images\icons
       Adds the file 128x128.png"="1/6/2021 9:13 AM, 1956 bytes, A
       Adds the file 16x16.png"="1/6/2021 9:13 AM, 365 bytes, A
       Adds the file 64x64.png"="1/6/2021 9:13 AM, 1156 bytes, A
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Extensions\hbfcbidlcbnolaphegpcpippkdpckihf\1.1.0_0\scripts
       Adds the file background.js"="11/16/2020 11:11 AM, 553430 bytes, A
       Adds the file sitecontent.js"="11/16/2020 11:11 AM, 77 bytes, A
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf
       Adds the file 000003.log"="1/6/2021 9:18 AM, 818 bytes, A
       Adds the file CURRENT"="1/6/2021 9:13 AM, 16 bytes, A
       Adds the file LOCK"="1/6/2021 9:13 AM, 0 bytes, A
       Adds the file LOG"="1/6/2021 9:13 AM, 183 bytes, A
       Adds the file MANIFEST-000001"="1/6/2021 9:13 AM, 41 bytes, A
    Adds the folder C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Web Applications\_crx_hbfcbidlcbnolaphegpcpippkdpckihf
       Adds the file PDFSearchHQ.ico"="1/6/2021 9:13 AM, 163385 bytes, A
       Adds the file PDFSearchHQ.ico.md5"="1/6/2021 9:13 AM, 16 bytes, A

Registry details [View: All details] (Selection)
       "hbfcbidlcbnolaphegpcpippkdpckihf"="REG_SZ", "6B497F7C7A31A15E6F12396B7345715FD8D1E6402F9BFE14E0D5021A67A6DE87"

Malwarebytes log:


-Log Details-
Scan Date: 1/6/21
Scan Time: 9:24 AM
Log File: a7391b60-4ff8-11eb-8551-080027235d76.json

-Software Information-
Components Version: 1.0.1130
Update Package Version: 1.0.35345
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: 232725
Threats Detected: 12
Threats Quarantined: 12
Time Elapsed: 2 min, 58 sec

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

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

Module: 0
(No malicious items detected)

Registry Key: 0
(No malicious items detected)

Registry Value: 1
Adware.SearchEngineHijack.Generic, HKCU\SOFTWARE\GOOGLE\CHROME\PREFERENCEMACS\Default\extensions.settings|hbfcbidlcbnolaphegpcpippkdpckihf, Quarantined, 15230, 799722, , , , , , 

Registry Data: 0
(No malicious items detected)

Data Stream: 0
(No malicious items detected)

Folder: 2
Adware.SearchEngineHijack.Generic, C:\USERS\{username}\APPDATA\LOCAL\GOOGLE\CHROME\USER DATA\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf, Quarantined, 15230, 799722, , , , , , 
Adware.SearchEngineHijack.Generic, C:\USERS\{username}\APPDATA\LOCAL\GOOGLE\CHROME\USER DATA\DEFAULT\EXTENSIONS\HBFCBIDLCBNOLAPHEGPCPIPPKDPCKIHF, Quarantined, 15230, 799722, 1.0.35345, , ame, , , 

File: 9
Adware.SearchEngineHijack.Generic, C:\USERS\{username}\APPDATA\LOCAL\GOOGLE\CHROME\USER DATA\Default\Secure Preferences, Replaced, 15230, 799722, , , , , 4F8F3EC6702661DA4056E9DB64B496C3, 58AC66BE2D76FD20AC080E649D3C1461D7069B9318734BA192026A4473376CF4
Adware.SearchEngineHijack.Generic, C:\USERS\{username}\APPDATA\LOCAL\GOOGLE\CHROME\USER DATA\Default\Preferences, Replaced, 15230, 799722, , , , , 973CDF83152930FE2C4EA648841CF232, A5E07D000E91A53F771D0D0AAD59A7A418138BCB98DDE63D5AFACE03E06FF84A
Adware.SearchEngineHijack.Generic, C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf\000003.log, Quarantined, 15230, 799722, , , , , 1A22301933EA217C3FA79F9F9AB76419, E50D165509495745D279A4414A60F3651FCCC971B5FB48211F835556AE4FFC39
Adware.SearchEngineHijack.Generic, C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf\CURRENT, Quarantined, 15230, 799722, , , , , 46295CAC801E5D4857D09837238A6394, 0F1BAD70C7BD1E0A69562853EC529355462FCD0423263A3D39D6D0D70B780443
Adware.SearchEngineHijack.Generic, C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf\LOCK, Quarantined, 15230, 799722, , , , , , 
Adware.SearchEngineHijack.Generic, C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf\LOG, Quarantined, 15230, 799722, , , , , 3BC31D03A2D419D3609CB4DA1A33114E, E618DF6F5BBBDFA85700FA021CE0297304D9552508D59B8693DA8F152BF082F0
Adware.SearchEngineHijack.Generic, C:\Users\{username}\AppData\Local\Google\Chrome\User Data\Default\Sync Extension Settings\hbfcbidlcbnolaphegpcpippkdpckihf\MANIFEST-000001, Quarantined, 15230, 799722, , , , , 5AF87DFD673BA2115E2FCF5CFDB727AB, F9D31B278E215EB0D0E9CD709EDFA037E828F36214AB7906F612160FEAD4B2B4
Adware.SearchEngineHijack.Generic, C:\USERS\{username}\APPDATA\LOCAL\GOOGLE\CHROME\USER DATA\DEFAULT\EXTENSIONS\HBFCBIDLCBNOLAPHEGPCPIPPKDPCKIHF\1.1.0_0\MANIFEST.JSON, Quarantined, 15230, 799722, 1.0.35345, , ame, , 4880A7C13558FC9C7CB30D328FE4D1FA, C90D2709DA3F6355BFCF7045847E9AD3AAFB12C5490F97B9EBE8F56356E30C5A
PUP.Optional.PushNotifications.Generic, C:\USERS\{username}\APPDATA\LOCAL\GOOGLE\CHROME\USER DATA\Default\Preferences, Replaced, 15847, 832955, 1.0.35345, , ame, , 973CDF83152930FE2C4EA648841CF232, A5E07D000E91A53F771D0D0AAD59A7A418138BCB98DDE63D5AFACE03E06FF84A

Physical Sector: 0
(No malicious items detected)

WMI: 0
(No malicious items detected)


As mentioned before the full version of Malwarebytes could have protected your computer against this threat.
We use different ways of protecting your computer(s):

  • Dynamically Blocks Malware Sites & Servers
  • Malware Execution Prevention

Save yourself the hassle and get protected.

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