MalwareTips
Threat LensFile scan report

Is sigma.exe safe?

Verdict
Malicious

42 of 75 engines flag this unsigned, brand-new executable with tier-1 consensus on Fragtor/XWorm activity.

Eight tier-1 engines and 42 total detections converge on Fragtor/XWorm families. The file is unsigned, appeared today, and shares its imphash with a previously malicious sample.

Do not run this file

Treat the file as malicious; delete it and scan any systems that came into contact with it.

Read the full analysis
Saved file evidenceAntivirus consensus
42of 75 flagged
Flagged 42No detection 33
Digital specimensigma.exe1143fd3c1f3138aa08…bcc67f02d12dc6
Size207.5 KB
Code signingUnsigned
SandboxPartial coverage
First seenToday
Evidence2 priority signals
42 of 75 antivirus engines flagged the file, including AhnLab-V3 and ALYac.

Recommended next actions

01

Before running

Do not run it. Delete this file from the device, then empty the Recycle Bin or Trash.

02

If you already ran it

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

Chapter 02

Intelligence

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

MT AI Engine · Verdict analysis

The reasoning behind this verdict

This section explains the evidence supporting the verdict and keeps conflicting or missing signals visible.

90%Confidence
Very high
Analyst conclusion

Eight tier-1 engines and 42 total detections converge on Fragtor/XWorm families. The file is unsigned, appeared today, and shares its imphash with a previously malicious sample.

Recommended action

Treat the file as malicious; delete it and scan any systems that came into contact with it.

Scan transparency

Coverage & freshness

3 of 5 complete

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

  • Antivirus

    Complete

    42 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

    Rule evaluation completed with no recorded matches.

  • External intel

    Complete

    3 of 3 independent reference sources completed.

Chapter 03

Behavior

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

Threat context

How remote-access malware works

This opens a secret 'back door' into your computer. Once it's running, an attacker can control your PC from anywhere — see your screen, read your files, switch on your webcam, install more malware, or use your machine to attack others.

Bottom line:It's built to stay hidden and keep that connection open for as long as possible.

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. Recovery step 01

    Don't run this file. Delete this file from the device, then empty the Recycle Bin or Trash.

  2. Recovery step 02

    If you already ran 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. Recovery step 03

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

  4. Recovery step 04

    Get a fresh copy from the developer's official site or an official app store.

Safety FAQ

Direct answers grounded in the saved verdict and evidence in this report.

8 evidence-based answers
Is sigma.exe malware?
Evidence-based answer
Yes — sigma.exe is malicious. Do not run it. Delete this file from the device, then empty the Recycle Bin or Trash. 42 of 75 antivirus engines flag it (family: fragtor). It behaves as a backdoor/remote-access trojan that lets an attacker control the device remotely. If you've already run it, see the removal and recovery steps below.
What is sigma.exe?
Evidence-based answer
sigma.exe is a Windows executable program (application/x-msdownload), about 208 KB. Our analysis identifies it as malicious (family: fragtor) — a backdoor/remote-access trojan that lets an attacker control the device remotely. 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 sigma.exe?
Evidence-based answer
42 of 75 antivirus engines flagged sigma.exe, 42 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 ran sigma.exe — what should I do?
Evidence-based answer
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 sigma.exe?
Evidence-based answer
To remove sigma.exe: 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) Delete this file from the device, then empty the Recycle Bin or Trash. 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 sigma.exe?
Evidence-based answer
sigma.exe is classified as a backdoor/remote-access trojan that lets an attacker control the device remotely. Engines attribute it to the fragtor 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.
What is the SHA-256 hash of sigma.exe?
Evidence-based answer
The SHA-256 hash of sigma.exe is 1143fd3c1f3138aa083d17cc8a7d70fca71e5238301f05b036bcc67f02d12dc6, and its MD5 is 4d15e52e7348b3115aab6039392b564e. 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 sigma.exe?
Evidence-based answer
This report reflects the scan run on August 21, 2026. Because a file's hash never changes, the identity of sigma.exe 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.
Chapter 06

Community

Member reviews and reports for this exact file hash.

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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.