MalwareTips
File verdict·Evidence-based file assessment

Our call: Is keylog.sys safe?Malicious

Do not use this component
12Safety ratingCritical risk
Rootkit.Agent.AJNQSignature valid · Microsoft Windows Hardware Compatibility Publ…
Evidence snapshot
  • 1 high-confidence signature or behavior rule matched this file.Observed · Signature and behavior rules
  • 11 of 75 antivirus engines flagged the file, including BitDefender and CTX.Observed · Antivirus analysis
  • The file has a valid code signature from Microsoft Windows Hardware Compatibility Publisher.Observed · Code-signing metadata
keylog.sys
52.7 KB
bb1b4e46f1e4a7f17b…e2656ba48b
Antivirus
11 of 75 flagged
Sandbox
Partial runtime
Code signing
Signed by Microsoft Windows Hardware Compatibility Publ…
First seen
First seen 23 days ago

Recommended next actions

01

Before using

Do not use it. Quarantine this component with your antivirus, then remove or repair it through the official driver, firmware, or device-software package. Do not delete the driver or firmware file manually.

02

If you already used it

Disconnect from the internet, start a full or offline antivirus scan, then secure important accounts from a clean device.

Scan transparency

Coverage & freshness

2 of 5 complete

Complete means the check returned a usable result. It does not mean the file is safe.

  • Antivirus

    Complete

    11 of 75 engines flagged the file.

  • Sandbox

    Partial

    Runtime data is present, but no completed sandbox environment is recorded.

  • Network

    Not run

    No contacted-host reputation check is recorded.

    No timestamp recorded

  • YARA

    Complete

    1 signature or behavior rule matched.

  • External intel

    Partial

    1 of 3 independent reference sources completed.

Chapter 02

Intelligence

The saved assessment, checked against the scan evidence and recorded coverage.

No saved analyst narrative

This report keeps the verified scan facts available below without inventing an analysis that was not saved with the scan.

Chapter 03

Behavior

Plain-English impact first, then the observed runtime evidence.

Threat context

How trojans work

A trojan disguises itself as something useful or harmless to trick you into running it. Once open, it does its real job in the background — anything from stealing data to opening a back door or downloading more malware.

Bottom line:The disguise is the whole trick, so a trustworthy-looking name or icon means nothing.

Chapter 04

Detection & Forensics

Consensus, attribution, signatures, code structure, prevalence, and identity.

Chapter 05

Safety & FAQ

Complete recovery guidance and answers for the next decision.

What to do now

This file is dangerous. Treat it as harmful and remove it.

  1. Don't use this component. Quarantine this component with your antivirus, then remove or repair it through the official driver, firmware, or device-software package. Do not delete the driver or firmware file manually.

  2. If you already used it, disconnect from the internet and start with a full antivirus scan or Microsoft Defender Offline scan. If compromise is suspected or the problem persists, use a reputable second-opinion scanner and follow incident-recovery or clean-reinstall guidance.

  3. If you typed any passwords while it was open, change them from a device you trust.

  4. Get a fresh driver or firmware package from the hardware or software manufacturer's official site.

Frequently asked

Safety FAQ

Is keylog.sys malware?
Yes — keylog.sys is malicious. Do not use it. Quarantine this component with your antivirus, then remove or repair it through the official driver, firmware, or device-software package. Do not delete the driver or firmware file manually. 11 of 75 antivirus engines flag it (family: Rootkit.Agent.AJNQ). It behaves as a trojan — malware disguised as something harmless to trick you into running it. If you've already used it, see the removal and recovery steps below.
What is keylog.sys?
keylog.sys is a system driver or firmware component, about 53 KB. Our analysis identifies it as malicious (family: Rootkit.Agent.AJNQ) — a trojan — malware disguised as something harmless to trick you into running it. Because a file's name and icon can be faked, the safest way to identify it is by its cryptographic hash (below), not its filename.
How many antivirus engines detected keylog.sys?
11 of 75 antivirus engines flagged keylog.sys, 11 of them as outright malicious. The raw count alone does not establish safety or danger; we also weigh which engines flagged it and corroborating behavior, identity, reputation, and rule evidence. The malicious verdict comes from the complete saved evidence, not from this antivirus count by itself.
I already downloaded and used keylog.sys — what should I do?
Act quickly. 1) Disconnect the device from the internet to stop the malware communicating or spreading. 2) Run a full scan with reputable anti-malware software (such as Malwarebytes) and quarantine everything it finds. 3) Change your important passwords from a DIFFERENT, clean device — many threats log keystrokes or steal saved credentials. 4) If you bank or shop on this device, watch closely for fraud and alert your bank. 5) For a confirmed infection, the most reliable fix is to back up your personal files and reinstall the operating system for a clean start.
How do I remove keylog.sys?
To remove keylog.sys: 1) restart into Safe Mode (Safe Mode with Networking if you need to download a tool) so the malware doesn't auto-start. 2) Run a full scan with reputable anti-malware software and let it quarantine or delete the detections. 3) Quarantine this component with your antivirus, then remove or repair it through the official driver, firmware, or device-software package. Do not delete the driver or firmware file manually. 4) Check your browser extensions, startup items, and scheduled tasks for anything unfamiliar. 5) Reboot and scan again to confirm it's gone. If detections keep coming back, a clean operating-system reinstall is the most dependable cure.
What kind of malware is keylog.sys?
keylog.sys is classified as a trojan — malware disguised as something harmless to trick you into running it. Engines attribute it to the Rootkit.Agent.AJNQ family. Knowing the family matters because it tells you the likely impact — data theft, remote control, file encryption, or unwanted ads — and guides the cleanup.
Is keylog.sys digitally signed?
Yes — keylog.sys carries a valid digital signature from Microsoft Windows Hardware Compatibility Publisher, which confirms the file hasn't been tampered with since that publisher signed it. A valid signature is a positive signal, but note that malware is occasionally signed with stolen or abused certificates, so it isn't proof of safety on its own.
What is the SHA-256 hash of keylog.sys?
The SHA-256 hash of keylog.sys is bb1b4e46f1e4a7f17b1b04ee08c33400b2b6fd2327612a4d84da81e2656ba48b, and its MD5 is 78f8396b9daf27d08aeec10539eeab56. This hash is the file's unique fingerprint — two files with the same SHA-256 are identical. Use it to confirm you're looking at exactly this file (not just one with the same name) when comparing against antivirus databases or a download's published checksum.
How up to date is this analysis of keylog.sys?
This report reflects the scan run on June 4, 2026. Because a file's hash never changes, the identity of keylog.sys is fixed — but antivirus coverage improves over time, so a file that looks clean today can pick up detections later (and vice-versa). If you need the latest picture, MalwareTips staff can re-run the analysis from scratch.
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The raw file is processed temporarily and is not retained after processing. Its hash and report are public and permanent, so the next person who checks the same file gets an instant answer. Unknown files may be submitted to VirusTotal for analysis. If you ran this file on your computer and are worried, scan your system with an up-to-date antivirus and change critical passwords from a different device.