How to remove AgtaBackup RAT from the operating system

What kind of malware is AgtaBackup RAT?

AgtaBackup RAT is a Remote Access Trojan (RAT) built on the .NET 8.0 platform. Once installed, it gives attackers complete, hidden control over the infected computer and can also steal saved passwords, cookies, and other sensitive data.

According to research published by Unit 42 (Palo Alto Networks), documented by researcher Ofek Lahiani, AgtaBackup RAT is deployed through a multi-stage campaign that starts with a fake software download page impersonating a video conferencing application.

The malware installs itself as a hidden Windows service and disguises its components using names that imitate legitimate Windows and hardware tools. There are no visible signs of infection - the victim typically has no idea anything is wrong.

AgtaBackup RAT overview

AgtaBackup RAT is a fully featured threat with a 10-mode operational dispatcher and 22 internal command endpoints. It stays in constant contact with its operator through two channels: an HTTP check-in that fires every two seconds and a WebSocket relay for real-time command delivery.

Shortly after starting, the RAT harvests saved credentials and cookies from nine browser families: Chrome, Edge, Brave, Opera, Opera GX, Vivaldi, Chromium, Yandex, and Firefox. It also scans for additional Chromium-based browsers installed on the machine. Collected data is compressed and sent to the attacker's server.

In addition to credential theft, the RAT runs a keylogger, captures screenshots, and opens a hidden interactive desktop session the developers call AgtaBackstage. Through this hidden session, attackers can issue commands and run shells invisibly, with the legitimate user unaware anything is happening.

AgtaBackup RAT features

AgtaBackup RAT's command set goes well beyond simple data theft. Operators can execute arbitrary PowerShell scripts, transfer files in either direction, kill running processes, manage Windows services, and take interactive control of the machine.

The browser credential harvester collects a wide set of profile files from each supported browser, covering saved logins, cookies, browsing history, bookmarks, and form data. Results are packed into a ZIP archive and uploaded to the attacker's server. The harvester runs two minutes after startup and repeats every five hours.

The keylogger runs as a separate binary in the active user session, recording every keystroke alongside context about the active process, window title, and website. A dedicated watchdog loop inside the RAT restarts the keylogger automatically if the process is terminated.

Persistence and evasion

Removing AgtaBackup RAT is intentionally difficult. Two scheduled tasks named AgtaBackupAgentWatchdog and AgtaBackupAgentGuardian run every minute as SYSTEM and automatically reinstall the RAT's Windows service within 60 seconds if it is stopped or deleted.

The service is registered with a restrictive permission descriptor that hides it from standard administrator accounts. Only the SYSTEM account itself can see or interact with the service, so normal management tools will not reveal its presence.

The main RAT binary is named Credential Guard.exe and its version metadata is set to impersonate a legitimate Windows security component. Support binaries use names such as Dell Window Guard.exe and Dell.Virus.Guard.exe, mimicking Dell hardware software.

The operator can push new filenames for the RAT's engine components at any time through the command-and-control server. This lets them rename binaries on the fly to defeat detection tools that rely on static filenames. An auto-update mechanism also downloads and silently installs new RAT versions as the developer releases them.

AgtaBackup RAT bypasses User Account Control (UAC) prompts by disabling the secure desktop setting in the Windows Registry and injecting keystrokes through a named pipe. This lets the attacker silently approve elevation dialogs without the user's knowledge.

Conclusion

AgtaBackup RAT gives attackers full control of an infected machine. They can steal every saved password and cookie, log all keystrokes, capture the screen, run scripts, and transfer files, all while hiding below the visibility of standard administrator tools.

The RAT's persistent watchdog tasks and service-hiding techniques make it very hard to remove manually. Victims face real risks of identity theft, account takeover, financial fraud, and follow-on malware infections. Any machine where AgtaBackup RAT is found should be treated as fully compromised and cleaned immediately. More examples of RATs are ChainScript, DarkTortilla, and NodeRabbit.

How did AgtaBackup RAT infiltrate my computer?

As documented by Unit 42, this campaign starts with a fake page designed to look like a Microsoft Store listing for a popular video conferencing application such as Zoom. The page delivers a legitimately signed remote monitoring and management (RMM) installer such as LogMeIn Resolve or ConnectWise ScreenConnect.

Once the victim installs the software and accepts the Windows UAC prompt, the RMM tool silently enrolls the computer in an attacker-controlled management account. Hours or even days later, the attacker connects through their RMM console, opens a remote terminal, and pastes a PowerShell command that silently downloads and installs AgtaBackup RAT.

More broadly, threats of this type also spread through phishing emails, pirated software downloads, fake cracks, and malicious advertisements. Always download software from official sources and treat unexpected installation prompts with caution.

How to avoid installation of malware?

Be cautious with unsolicited emails, direct messages, and links - especially those that push you to download or install something quickly. Only download software from official developer websites or trusted app stores. Avoid pirated content, key generators, and unofficial activation tools, as these are common malware delivery vehicles.

Keep your operating system and all installed applications up to date, since attackers frequently exploit known vulnerabilities in unpatched software. Use a reputable security suite and run regular scans to catch threats early. If you believe that your computer is already infected, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

How to remove malware manually?

Most trojan infections can be removed by running a full system scan with Combo Cleaner. The full manual procedure below is for cases where automatic removal failed, where you want to verify a scan caught everything, or where the threat has multiple persistence points.

Tools you'll need

Combo Cleaner Antivirus 7-days free trial

Recommended primary scanner. VB100 certified. The 7-day free trial is available.

Microsoft Defender Offline Free · built-in

Built into Windows. Boots to a clean environment to catch rootkits.

Process Explorer Free

From Microsoft Sysinternals. Better than Task Manager - shows full paths and signatures.

Autoruns Free

From Microsoft Sysinternals. Lists every place malware can persist on your system.

Microsoft Safety Scanner (MSERT) Free

Official Microsoft on-demand scanner. Always-current signatures - expires every 10 days.

Phase 1~ 5 min

Contain - limit the damage

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1

Disconnect from the network

30 secNo tool needed

Unplug your Ethernet cable and turn off Wi-Fi. If you're on a laptop, the airplane-mode key works fastest.

Why this matters

Many trojans exfiltrate data - saved browser passwords, banking sessions, screenshots - and accept remote commands. Cutting the network stops both immediately. Keep it disconnected until Phase 4.

2

Boot into Safe Mode with Networking

3 min

Safe Mode loads a minimal set of drivers and stops most malware from auto-running. "With Networking" lets you download tools - re-enable Wi-Fi only after you've booted in.

Windows 11

Open Settings → System → Recovery. Click Restart now next to Advanced startup.

Your computer will restart into the "Choose an option" menu. Click Troubleshoot → Advanced options → Startup Settings → Restart. After the second reboot, press 5 or F5.

Windows 10

Click the Windows logo, hold Shift, click the Power icon and choose Restart. In the Choose an option screen, click Troubleshoot → Advanced options → Startup Settings → Restart. Press F5.

Windows 8

Go to the Start Screen, type Advanced, select Settings → Advanced startup options → Restart now → Troubleshoot → Advanced options → Startup settings → Restart → F5.

Note: Windows 8 reached end-of-life in January 2023 - running on it puts you at much higher risk of reinfection.

Windows 7

Click Start → Shut Down → Restart → OK. As the system boots, press F8 repeatedly until the Windows Advanced Options menu appears, then choose Safe Mode with Networking.

Note: Windows 7 reached end-of-life in January 2020 - running on it puts you at much higher risk of reinfection.

Phase 2~ 15 min

Identify - find what's hiding

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3

Inspect running processes with Process Explorer

Tool: Process Explorer5 min

Download Process Explorer from Microsoft Sysinternals. Run it as Administrator. Click Options → Verify Image Signatures and View → Lower Pane View → DLLs.

Sort by "Verified Signer." Anything unsigned running from %AppData%, %LocalAppData%, %Temp%, or %ProgramData% is suspicious. Right-click → Properties to see the full image path. Right-click → "Search Online" to look up unfamiliar process names.

Why not just Task Manager

Task Manager hides full file paths, doesn't show digital signatures, and groups processes in ways that make malware easy to miss. Process Explorer is the same tool Microsoft engineers use.

4

Map every persistence point with Autoruns

Tool: Autoruns 14.x10 min

Download Autoruns. Right-click Autoruns.exe and choose Run as administrator - without elevation, Autoruns can't inspect protected registry hives.

In the menu, open Options → Hide Microsoft Entries and Options → Hide Empty Locations, then click Refresh.

Modern trojans don't just live in startup. Walk through these tabs and look for unsigned or unfamiliar entries:

• Logon - classic Run/RunOnce keys
• Scheduled Tasks - frequent hiding spot, especially tasks with PowerShell, MSHTA, or rundll32 actions
• Services - unsigned services in non-Microsoft folders
• WMI - Event Subscriptions are a stealthy persistence mechanism (MITRE T1546.003)
• Image Hijacks - Image File Execution Options "Debugger" abuse
• AppInit - DLLs loaded into every GUI process
• Browser plug-ins - unsigned add-ons across all installed browsers

Pro tip

Right-click any suspicious entry → "Jump to Image" to see the actual file. Right-click → "Search Online" opens VirusTotal for the file hash. Don't delete yet - just write down the file paths and entry names. We'll remove them after the scans.

5

Check the hosts file and DNS settings

3 minBuilt into Windows

Trojans often redirect bank, antivirus, and update domains to attacker-controlled servers by editing the hosts file or DNS settings.

Hosts file: Open Notepad as Administrator and open C:\Windows\System32\drivers\etc\hosts. Legitimate entries are commented with #. Any uncommented IP-to-domain mapping is suspicious - especially redirects for microsoft.com, windowsupdate, or your bank.

DNS settings: Open Command Prompt as Administrator and run ipconfig /all. Confirm your DNS servers point to your ISP, your router, or a known public resolver (Cloudflare 1.1.1.1, Google 8.8.8.8). Then open Settings → Network & internet → [your adapter] → DNS server assignment and verify both DNS and DNS over HTTPS (DoH) settings haven't been hijacked.

Why this matters

A clean PC with hijacked DNS is still a compromised PC. You'll think you're at chase.com and you'll be at the attacker's clone.

Phase 3~ 60-90 min

Remove - three scans, one cleanup

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No single antivirus catches everything. The order below is intentional: offline scan first (catches rootkits before Windows fully loads), then on-demand scanners on the running system, then manual cleanup of anything they missed.

6

Run Microsoft Defender Offline

Tool: Built into Windows15 min

Reboot to normal Windows. Open Windows Security → Virus & threat protection → Scan options. Select Microsoft Defender Antivirus (offline scan) and click Scan now. Your computer will restart into a stripped-down environment and scan before the full operating system loads.

Why this comes first

Rootkits and bootkits hide from any scanner running on the same Windows session that's already infected. A pre-boot offline scan sees the disk before the malware can hide itself.

Recommended antivirus

Combo Cleaner

VB100 certified. Includes anti-trojan, registry/persistence scanning, anti-spyware in one pass. The 7-day free trial is available.

Download Combo Cleaner

7

Run Combo Cleaner full system scan

Tool: Combo Cleaner20-40 min

Install Combo Cleaner and run a full system scan (not the quick scan). Let it complete fully, review the detected threats, and apply the recommended actions. Combo Cleaner will quarantine known trojans and registry persistence.

8

Run Microsoft Safety Scanner as a second-opinion scan

Tool: Microsoft Safety Scanner15 min

Download Microsoft Safety Scanner (MSERT.exe), Microsoft's free on-demand tool. The binary expires every 10 days, which means every download has the latest signatures. Run a full scan after Combo Cleaner to catch anything one engine alone might miss.

Why a second scan

Different scanning engines catch different threats. Running an additional Microsoft scan after Combo Cleaner is the single most underused verification step in malware removal.

9

Manually remove anything still listed in Autoruns

Tool: Autoruns10 min

Reopen Autoruns. Anything you flagged in Step 4 that's still present hasn't been caught by the automated scans. For each remaining suspicious entry: right-click → Delete in Autoruns (this removes the persistence registration), then navigate to the file path and delete the actual file. Empty the Recycle Bin.

Important

Some malware files reappear after deletion because something else on the system recreates them. If you delete a file and it returns within minutes, you have a remaining persistence point that Autoruns didn't show - usually a service or scheduled task running under SYSTEM. Re-run the scans from Steps 6-8 or proceed to a clean install (see end of guide).

Phase 4~ 15 min

Recover - restore browsers and security

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10

Reset browsers and clear notification permissions

5 min

Trojans and adware frequently hijack browsers - change the default search engine, install rogue extensions, or grant themselves notification permissions to keep displaying scam pop-ups even after the malware is gone.

• Chrome: visit chrome://settings/reset and click "Restore settings to their original defaults." Then visit chrome://settings/content/notifications and remove any unfamiliar sites.
• Edge: visit edge://settings/reset. Then check edge://settings/content/notifications.
• Firefox: open about:support and click Refresh Firefox (Firefox uses "Refresh," not "Reset"). Then check Settings → Privacy & Security → Permissions → Notifications.

Review installed extensions in each browser and remove anything you don't recognize, especially extensions you didn't install yourself.

11

Re-enable Defender, Tamper Protection, and update everything

10 min

Many trojans disable security software. Open Windows Security → Virus & threat protection → Manage settings and confirm Real-time protection, Cloud-delivered protection, and Tamper Protection are all turned on. Tamper Protection prevents malware from disabling Defender silently.

Then run Windows Update (Settings → Windows Update → Check for updates) and update your browsers and applications. The infection vector that let the trojan in originally usually involves outdated software.

Phase 5~ 15 min + 7 days

Verify & secure

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12

Change passwords from a clean device

20 min⚠ Critical

If the trojan was an info-stealer (Lumma, RedLine, Vidar, and similar are extremely common), assume every password saved in your browser is compromised. Change them from a different, known-clean device - your phone is fine if it's not infected.

Recommended order:

1. Primary email first - it's the recovery hub for everything else
2. Banking and financial accounts
3. Password manager master password (if you use one)
4. Social media, shopping, and remaining accounts

Where available, enable phishing-resistant multi-factor authentication (passkeys / FIDO2 hardware keys / authenticator apps) - SMS-based MFA is bypassable by sophisticated attackers.

13

Verify the clean and monitor for 7 days

5 min + 1 week monitoring

Reconnect to the network and run one final full scan with Combo Cleaner. Open Task Manager (Ctrl + Shift + Esc) and switch to the Startup apps tab - confirm nothing suspicious has reappeared.

Over the next 7 days, watch for symptom recurrence: unexpected high CPU usage, unknown processes returning, browser redirects, or pop-ups. If anything returns, you missed a persistence point and the procedure needs to be repeated - or you may have a deeper compromise that requires a clean install.

When to clean install Windows instead

Manual removal isn't always the right answer. Reinstalling Windows from scratch is the only way to be 100% certain when:

• The malware reappears after every removal attempt
• A bootkit or UEFI rootkit was detected (this class of threat sits below the operating system and survives a normal Windows reinstall)
• A confirmed credential-theft trojan ran with administrator privileges (Lumma, RedLine, Vidar) - the system likely has multiple unknown payloads
• The PC is used for online banking, business email, or anything where partial doubt isn't acceptable

A clean install is a 30-60 minute process: Windows 11 reinstall via Settings → System → Recovery → Reset this PC → Remove everything → Cloud download. Back up documents to external storage first, scan the backup with Combo Cleaner before restoring it, and reinstall applications fresh - never restore them from a backup of the infected system.

Important: Manual removal requires advanced computer skills. If you're not confident identifying system files from malicious files, run an automated scan with Combo Cleaner and Windows Defender and stop there - that path catches the vast majority of consumer trojans without the risk of breaking Windows by deleting the wrong file.

Frequently Asked Questions (FAQ)

My computer is infected with AgtaBackup RAT malware, should I format my storage device to get rid of it?

Formatting the storage device will remove AgtaBackup RAT, but it will also erase every file on the drive. Running a trusted security tool like Combo Cleaner should be tried first, since it can remove the infection without destroying your data.

What are the biggest issues that AgtaBackup RAT malware can cause?

AgtaBackup RAT gives attackers full remote control and can steal credentials, log keystrokes, transfer files, and install additional malware. This puts victims at risk of identity theft, account takeover, financial fraud, and loss of sensitive data.

What is the purpose of AgtaBackup RAT malware?

The purpose of AgtaBackup RAT is to give attackers persistent, hidden remote control over infected machines. Operators can spy on users, steal credentials from browsers, log keystrokes, run commands, and stage follow-on attacks, all while remaining undetected.

How did AgtaBackup RAT malware infiltrate my computer?

AgtaBackup RAT has been observed spreading through a fake software download page that impersonates a video conferencing app and tricks the user into installing a legitimate remote management tool. The attacker then uses that tool to silently deploy the RAT.

More generally, threats of this type also reach victims through phishing emails, pirated software, and fake software cracks.

Will Combo Cleaner protect me from malware?

Yes. Combo Cleaner can detect and remove most known malware, including threats like AgtaBackup RAT. Because some high-risk threats hide deeply in the system, running a full scan rather than a quick scan is the safest approach.