How to remove JaskaGO malware from compromised computers

What kind of malware is JaskaGO?

JaskaGO is a sophisticated stealer written in Go (Golang) programming language targeting Windows and macOS systems. With extensive commands from its Command and Control server, the malware excels at extracting valuable information, exposing users to a heightened risk of data compromise, including browser credentials and sensitive files.

More about JaskaGO

The initial sighting of the JaskaGo sample occurred in July 2023, with an initial focus on Mac users. Upon its first activation, the malware cleverly generates a misleading message containing a fabricated error, indicating a supposedly missing file. This tactic aims to deceive the user into thinking that the malicious code encountered an error and did not execute as intended.

The malware checks if it is in a virtual machine (VM) by looking at general machine details like processors, system up-time, memory, and MAC addresses. If it finds MAC addresses linked to popular VM software, such as VMware or VirtualBox, it signals a likely VM. The Windows version of the malware also searches for VM traces in the registry and file system.

If it does not detect a VM, JaskaGO gathers information from the victim and connects to its command and control for more actions.

The malware consistently checks its command and control server for instructions, which can involve various actions such as establishing persistence, stealing information from the infected device, pinging the command and control, executing shell commands, displaying alerts, and retrieving running processes.

Also, those commands include running files on disk or in memory, writing to the clipboard (commonly for stealing cryptocurrency funds), performing random tasks, downloading and executing additional payloads, and initiating the process to exit or exit and self-delete.

JaskaGO is equipped with robust data exfiltration capabilities, storing acquired data in a dedicated folder before compressing and sending it to the malware's threat actor when ready. It functions as a browser stealer, targeting Chrome and Firefox by default but configurable for additional browsers, capturing credentials, history, cookies, password encryption keys, profile files, and login information.

The malware extends its reach to cryptocurrency theft, searching for crypto wallets in browser extensions. Additionally, it can exfiltrate specified files and folders as directed.

Conclusion

In conclusion, JaskaGO represents a sophisticated threat with potent data exfiltration capabilities. Its versatility includes browser and cryptocurrency theft, as well as the ability to exfiltrate specific files and folders as directed by its command and control. The malware's intricate functionalities underscore the importance of robust cybersecurity measures to mitigate its potential impact on user data and system security.

More examples of malware capable of stealing information are Editbot, MrAnon, and Vare.

How did JaskaGO infiltrate my computer?

Threat actors employ various deceptive tactics to trick users into unwittingly infecting their computers with malware. One common method involves phishing emails, where attackers send seemingly legitimate messages with malicious links or attachments. They aim to trick users into clicking links or downloading attachments, leading to malware execution.

Another tactic is the use of malicious websites and online ads. Cybercriminals create websites or advertisements that appear genuine, enticing users to click on them. Once clicked, these sites may execute drive-by downloads or prompt users to download seemingly innocuous files, which, in reality, contain malicious code.

Other avenues utilized for malware distribution include pirated software, key generators, cracking tools, third-party downloaders, P2P networks, infected USB drives, unofficial app stores, and similar channels.

How to avoid installation of malware?

Install trustworthy antivirus and anti-malware software, and conduct regular computer scans to detect potential threats. Make sure that your operating system, software applications, and antivirus programs receive regular updates to maintain robust security.

Exercise caution when dealing with email attachments and links, particularly if the email is from an unexpected or unknown sender. Avoid downloading software, files, or applications from untrustworthy or unfamiliar websites. Opt for reputable sources to reduce the likelihood of downloading malware.

Steer clear of interacting with ads, pop-ups, and similar content on questionable websites to minimize the risk of encountering malicious elements. 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.

Fake error message displayed upon the execution of JaskaGO (malicious executable):

Text in this error:

Missing DLL

VCLRS.dll Not Found May Some Features Don't Work Like Expected

Update 17 January 2024: The infostealers targeting macOS, namely KEYSTEAL, Atomic, and JaskaGo, underscore the persistent and adaptive nature of cybersecurity threats. Despite Apple's proactive measures, these malware variants exhibit continuous evolution, employing tactics such as code signature alterations, distribution method changes, and shifts in malicious behavior.

The threat landscape is characterized by the ability of these infostealers to evade static signature detection engines, emphasizing the importance of dynamic and advanced threat hunting techniques.

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

---

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

---

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

---

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

---

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

---

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 JaskaGO malware, should I format my storage device to get rid of it?

Utilizing device formatting can effectively eliminate the JaskaGO malware from your computer. Nevertheless, it's essential to acknowledge that formatting leads to the complete loss of all data. Therefore, it is advisable to explore alternative options, such as employing reputable antivirus or anti-malware software to scan and cleanse your system thoroughly.

What are the biggest issues that malware can cause?

The impact of malware varies based on its type and can result in consequences like identity theft, financial losses, diminished computer performance, and the potential for additional infections.

What is the purpose of JaskaGO malware?

The purpose of JaskaGO is to compromise system security by deceiving users, detecting virtual machines, gathering information, interacting with a command and control server, exfiltrating sensitive data (including cryptocurrency-related information), executing various commands, and establishing persistence on infected systems.

How did a malware infiltrate my computer?

The precise approach of malware infiltration may differ, with typical vectors encompassing malicious email attachments, compromised websites, software vulnerabilities, malicious advertisements, unauthorized software downloads, peer-to-peer (P2P) networks, and infected USB drives.

Will Combo Cleaner protect me from malware?

Combo Cleaner possesses the capability to identify and eradicate nearly all malware infections. It is vital to acknowledge that sophisticated malware often conceals itself within the system. Consequently, conducting a thorough system scan is imperative for comprehensive detection and elimination.