PC Infected with Persistent Malware Downloading Files Hourly

[tanner_doriano]

Hello Malwarebytes Community,

I'm in a bit of a bind and desperately need your expertise. Two days ago, around 6:30-7:00 PM (GMT +8), I mistakenly executed a file I downloaded from the Internet. Only after running it did I realize its malicious intent, evident from a suspicious pre-build event in the code. (I cannot post the code here because it might tag my post as malicious.)

Since then, my PC has been automatically downloading a .7z file to the "AppData/Local/Temp" folder every hour on the hour. This archive contains "aitstatic.exe", "ComSvcConfig.exe", and "MicrosoftCertificateServices.exe." Additionally, every time I start my computer, 2-3 command prompt windows briefly appear, and files named "Service.exe", "b.bat", and "b.vbs" are created in various public user folders (e.g., Public Downloads, Public Documents) also every hour on the hour.

I've attempted to clean this infection with both Malwarebytes and Avast, but to no avail. The threat names reported by Avast vary, including IDP.HELU.SHADOW18, Script:SNH-gen [Trj], Win64:Malware-gen, and Win32:InjectorX-gen [Trj].

I am at my wit's end and worry about the safety of my personal data and the integrity of my system. Could anyone provide guidance on how to thoroughly remove this persistent malware? Any assistance or advice on tools and procedures to follow would be immensely appreciated.

Thank you in advance for your time and help.

[JSntgRvr]

Welcome.

Please download the Farbar Recovery Scan Tool and save it to your desktop.

Note: You need to run the version compatible with your system.
You can check here if you're not sure if your computer is 32-bit or 64-bit

• Please rename FRST.EXE or FRST64.EXE to FRSTEnglish.exe
• After renaming the file right-click over FRSTEnglish.exe and select "Run as administrator"
• When the tool opens click Yes to the disclaimer if this is the first time using the tool
• Make sure there is a check mark in the Addition.txt check box
• Press the Scan button.
• It will make a log FRST.txt and Addition.txt in the same directory the tool is run from. Please attach both logs to your next reply.

[tanner_doriano]

I have attached both the "FRST.txt" and "Addition.txt" logs from the Farbar Recovery Scan Tool as you instructed. Both logs are now ready for your review.

FRST.txt Addition.txt

[JSntgRvr]

Welcome 
 
I'll be helping you with your computer.
 
Please read this post completely before beginning. If there's anything that you do not understand, please don't hesitate to ask before proceeding.
 
Please take note of the guidelines for this fix:

• Please note that I am a volunteer. I do have a family, a career, and other endeavors that may prevent immediate responses that meet your schedule. Do note that the differences in time zones could present a problem as well. Your patience and understanding will be greatly appreciated.
• First of all, the procedures we are about to perform are specific to your problem and should only be used on this specific computer.
• Do not make any changes to your computer that include installing/uninstalling programs, deleting files, modifying the registry, nor running scanners or tools of any kind unless specifically requested by me.
• Please read ALL instructions carefully and perform the steps fully and in the order they are written.
• If things appear to be better, let me know. Just because the symptoms no longer exist as before, does not mean that you are clean.
• Continue to read and follow my instructions until I tell you that your machine is clean.
• If you have any questions at all, please do not hesitate to ask before performing the task that I ask of you, and please wait for my reply before you proceed.
• Scanning with programs and reading the logs do take a fair amount of time. Again, your patience will be necessary. 

Let's begin... 

This Fix will empty the following folders:

• Windows Temp
• Users Temp folders
• Edge, IE, FF, Chrome, and Opera caches, HTML5 storages, Cookies and History
• Recently opened files cache
• Discord cache
• Java cache
• Steam HTML cache
• Explorer thumbnail and icon cache
• BITS transfer queue (qmgr*.dat files)
• Recycle Bin

Important: items are permanently deleted. They are not moved to quarantine. If you have any questions or concerns please ask before running this fix.

The system will be rebooted after the fix has run.

• Download the enclosed file  Fixlist.txt
• Save it in the same location FRST64.exe is saved
• Start FRST (FRST64) with Administrator privileges 
• This time around Press the Fix button and wait
• When finished, a log file (Fixlog.txt) will pop up and saved in the same location the tool was ran from.

Please attach this file in your next reply.

Re-test and let me know the outcome.

[tanner_doriano]

I have attached the "Fixlog.txt" file as instructed and have retested as you requested. Additionally, I've attached the new logs generated after retesting. Despite following the steps and running the fix, when I waited for the next hour, the system still attempted to perform its scheduled download. It appears the issue persists despite the applied fix.

Fixlog.txtFRST.txtAddition.txt

[JSntgRvr]

Found an entry never seen before.

The system will be rebooted after the fix the following Fix.

• Download the enclosed file  Fixlist.txt
• Save it in the same location FRST64.exe is saved
• Start FRST (FRST64) with Administrator privileges 
• This time around Press the Fix button and wait
• When finished, a log file (Fixlog.txt) will pop up and saved in the same location the tool was ran from.

Please attach this file in your next reply.

Lets try an online scanner:

Dr.Web CureIt!

Please download the Dr.Web CureIt! anti-virus utility
https://free.drweb.com/

 

You will need to send them an email to obtain a link to download the scanner, please do so

• The downloaded file will normally have a unique name such as:  q7a9tr4p.exe
• Close all open applications and locate the downloaded file and double-click to run it
• The program will take a moment to launch and bring up the License and Update screen
• Place a check mark to agree to the terms and then click on the Continue button
• Click the underlined link Select objects for scanning
• On the top left click the Scanning objects that should automatically check all objects
• Click the small wrench and make sure there is a check on Automatically apply actions to threats
• Then click the large button on bottom right Start scanning
• Once the scan has completed there will be a link named Open report click that and a log named cureit.log should open in Notepad
• The log is saved in the folder named Doctor Web in the top of your user profile folders
• Please attach that log on your next reply

[JSntgRvr]

Do you still need help?