Step-by-Step: Removing OneHalf Virus Killer Without Losing Files

Step-by-step: Removing OneHalf Virus Killer Without Losing Files

1) Immediately isolate the infected PC

• Disconnect from Wi‑Fi and unplug Ethernet.
• Do not shut down if files are open; instead disconnect network to stop lateral spread.

2) Preserve evidence and make images

• Create disk image backups of affected drives (use dd, Macrium Reflect, or similar).
• Work from copies—never modify the original disk.

3) Identify the ransomware

• Collect ransom note text, file extensions added to encrypted files, and any executable names.
• Use online ID tools (Emsisoft, NoMoreRansom, ID Ransomware) to match the strain.

4) Check for available decryptors

• If identification returns OneHalf (or a known variant), check:
  • NoMoreRansom (Kaspersky)
  • Emsisoft decryptors
  • Vendor advisories (TrendMicro, Malwarebytes)
• If a decryptor exists, read its instructions fully before running.

5) Remove the malware (without touching encrypted files)

• Boot into safe mode or use a clean rescue USB environment.
• Run up-to-date offline antivirus/anti‑malware scans (Kaspersky Rescue Disk, Malwarebytes, ESET Online Scanner).
• Remove all malicious executables, scheduled tasks, and persistence mechanisms.
• Verify persistence is gone before restoring files.

6) Verify backups and restore plan

• Confirm you have clean, recent backups stored offline or on an air-gapped device.
• If backups exist and are clean, restore from them after confirming the system is malware-free.

7) Attempt decryption (only after malware removal)

• Run official decryptor for the identified strain per vendor instructions (always on copies of encrypted files first).
• If decryptor fails, do not run random tools—consult vendor guidance or security forums (Emsisoft, NoMoreRansom).

8) If no decryptor and no clean backup

• Do not pay ransom (law enforcement and most security experts advise against it).
• Preserve copies of encrypted files and system images.
• Monitor NoMoreRansom and vendor advisories—decryptors sometimes become available later.
• Consider professional incident response if the data is critical.

9) Recover and harden

• After files restored or decrypted: reinstall OS or reimage systems if there’s any doubt about cleanup.
• Change all passwords and revoke/reissue credentials used on the infected machine.
• Patch OS and applications, enable disk and endpoint backups (offline & versioned), and deploy endpoint protection and EDR.

10) Report incident

• Report to local law enforcement and, if applicable, your national cybercrime center.
• Share indicators (file samples, ransom notes, hashes) with security vendors to help others.

If you want, I can:

• provide specific OneHalf detection indicators and known decryptor links (I’ll fetch vendor pages), or
• give exact commands/tools for imaging and scanning on Windows or Linux. Which do you prefer?