How to remove SilentSync from computers

Trojan

Also Known As: SilentSync remote administration trojan

(updated)

Damage level:

Get free scan and check if your device is infected.

Remove it now

To use full-featured product, you have to purchase a license for Combo Cleaner. Seven days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.

What kind of malware is SilentSync?

SilentSync is a Python-based remote access Trojan (RAT) targeting multiple operating systems. It allows cybercriminals to steal sensitive information and perform other malicious tasks. If detected on a device, SilentSync should be removed using a reliable security tool as soon as possible to avoid the potential negative consequences.

SilentSync malware

More about SilentSync

Once infiltrated, SilentSync is designed to stay active on an infected computer by setting itself up to run automatically whenever the system restarts or the victim logs in. It uses different methods depending on the operating system. It is worth noting that only Windows machines are vulnerable to SilentSync at this time.

On Windows, SilentSync adds a registry key called PyHelper so the malware launches when the user logs in. On Linux, the malware edits the crontab with a specific command to start the payload after each boot. On macOS, it drops a file named com.apple.pyhelper.plist into the LaunchAgents folder, making the system load it at login.

Furthermore, as a RAT, SilentSync can execute various commands on the infected device, steal files (single files and folders), delete copies of stolen files after exfiltration, take screenshots of the desktop, and steal information from web browsers (on Windows only).

The targeted browsers are Brave, Chrome, Edge, and Firefox. SilentSync can steal browsing history, autofill data, cookies, and saved passwords from these browsers. Overall, cybercriminals can use SilentSync to take over online accounts, commit identity theft, steal money, and more.

Threat Summary:
Name SilentSync remote administration trojan
Threat Type Remote Access Trojan
Detection Names Avast (Other:Malware-gen [Trj]), Combo Cleaner (Trojan.GenericS.9580), ESET-NOD32 (Python/Agent.BVA), Kaspersky (HEUR:Trojan-PSW.Python.Agent.gen), VIPRE (Trojan.GenericS.9580), Full List (VirusTotal)
Symptoms Remote Administration Trojans are designed to stealthily infiltrate the victim's computer and remain silent, and thus no particular symptoms are clearly visible on an infected machine.
Possible distribution methods fake Python packages on PyPI.
Damage Stolen passwords and banking information, identity theft, monetary loss, possible additional infections.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner.

Download Combo Cleaner

To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.

Conclusion

SilentSync is a dangerous remote access trojan (RAT) disguised inside malicious Python packages. It infiltrates systems unnoticed, establishes persistence, and communicates with an attacker-controlled server. Once active, it can run commands, capture screenshots, steal browser data, and exfiltrate files.

This can cause issues like monetary loss, identity theft, additional infections, account hijacking, and other serious issues. Thus, it is important to be careful online to avoid threats like SilentSync.

More examples of RATs are ZynorRAT, kkRAT, and GodRAT.

How did SilentSync infiltrate my computer?

SilentSync spreads through fake Python packages on PyPI, which pretend to be real libraries like sisaws (mimicking the behavior of the legitimate sisa package for Argentina's healthcare services). When a developer installs one of these packages, a hidden backdoor code runs and deploys SilentSync.

Other common ways malware spreads include fake emails containing harmful attachments or links, software vulnerabilities, malicious online ads, peer-to-peer (P2P) networks, tech support scams, and third-party downloaders, deceptivve or compromised pages, and similar channels.

How to avoid installation of malware?

Always get software and files from official websites or reputable app stores. Avoid pirated programs or tools that bypass software activation. Keep your operating system, browsers, and apps up to date, and use trusted security software to protect your device.

Do not open attachments or click links in unexpected emails or messages, especially from unknown senders. Avoid clicking on suspicious ads, pop-ups, and similar content, and never allow notifications from untrustworthy sites.

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.
Built into Windows. Boots to a clean environment to catch rootkits.
From Microsoft Sysinternals. Better than Task Manager - shows full paths and signatures.
From Microsoft Sysinternals. Lists every place malware can persist on your system.
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.

Run Windows 11 in Safe Mode with Networking
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.

Run Windows 10 in Safe Mode with Networking - press F5 at the Startup Settings screen
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.

Process Explorer showing a suspicious unsigned process running from %AppData%
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.

Autoruns 14.x with Hide Microsoft Entries enabled showing the Logon and Scheduled Tasks tabs
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.

Combo Cleaner full scan results showing detected threats
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.

Verifying malware removal in the Windows 11 Task Manager Startup apps tab

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

Formatting will remove SilentSync, but a full system scan with a trusted tool like Combo Cleaner is usually enough to detect and eliminate it without losing all data.

What are the biggest issues that malware can cause?

Malware can cause financial loss, data theft, identity fraud, system damage, further infections, and other issues.

What is the purpose of SilentSync?

SilentSync can run commands, steal files and folders (then delete local copies), capture desktop screenshots, and extract data from web browsers on Windows. It targets Brave, Chrome, Edge, and Firefox to steal history, autofill data, cookies, and saved passwords.

How did SilentSync infiltrate my computer?

SilentSync spreads via fake Python packages on PyPI that mimic legitimate libraries. When installed, they execute hidden backdoor code that deploys the malware.

Will Combo Cleaner protect me from malware?

Yes, Combo Cleaner is able to detect and remove most known malware. Still, advanced threats often hide deep in the system, which makes running a full system scan crucial.

Share:

facebook
X (Twitter)
linkedin
copy link
Tomas Meskauskas

Tomas Meskauskas

Expert security researcher, professional malware analyst

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats.

▼ Show Discussion

PCrisk security portal is brought by a company RCS LT.

Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.

Our malware removal guides are free. However, if you want to support us you can send us a donation.

Donate