Removing Locky ransomware and tracing how it got in

Locky is a file-encrypting ransomware family that first appeared in large-scale spam campaigns and later evolved through multiple delivery methods. It typically encrypts documents, images, databases, archives, and other valuable files, then leaves ransom notes instructing the victim to pay for a decryption key.

Removing the malware stops further damage, but it does not automatically restore encrypted data. The safest response separates three tasks: isolate the infected computer, preserve evidence about the infection path, and clean or rebuild the system before attempting recovery.

The original delivery route is especially important. Knowing whether Locky arrived through a malicious document, script, compromised website, or another downloader can reveal which accounts, endpoints, and email recipients may also be at risk.

What Locky did to the system

Locky variants commonly searched connected drives and user folders for files with business or personal value. Encrypted files could receive unusual extensions, while ransom instructions were saved as HTML, text, or image files. The exact extension and note wording varied between campaigns, so these signs alone do not prove a particular variant.

A sudden wave of inaccessible files, renamed documents, high disk activity, and a ransom note is a strong indicator of ransomware. Security software may also report a suspicious executable, script interpreter, macro-enabled document, or process launched from a temporary user directory.

Do not open ransom notes in a browser connected to the internet, run attached scripts, or pay before investigating. Payment offers no reliable guarantee of recovery and can expose victims to additional fraud.

How to identify the drop mechanism

Locky was frequently distributed through malicious email attachments, including Word documents with harmful macros, JavaScript files, compressed archives, and executable payloads. Some campaigns used seemingly legitimate invoices, shipping notices, or payment documents to persuade recipients to enable content or extract an attachment.

The “dropper” is the first malicious component that places or launches the ransomware. Investigators can examine email headers, attachment names, file timestamps, browser download history, and endpoint protection alerts. A process tree may show a chain such as an email client opening a document, the document starting a script interpreter, and that script launching a downloader or ransomware binary.

Other possible entry points include exploit kits, stolen remote-access credentials, malicious advertising, and previously installed trojans. Check whether the same suspicious file appeared on other computers, whether a scheduled task was created, and whether remote services recorded an unusual login shortly before encryption.

Contain the infection before cleanup

Immediately disconnect the affected computer from wired and wireless networks. Unplug mapped storage and external backup drives, but avoid browsing their contents from the infected system. If several devices show symptoms, isolate each one and notify the person responsible for network administration.

Do not delete suspicious files before collecting basic evidence if an investigation may be necessary. Record the ransom note name, encrypted-file extension, time of discovery, affected folders, alert details, and the original email or download source. Take photographs or screenshots if opening the infected system could change evidence.

If the computer is business-owned, involve an incident-response professional before making major changes. A forensic copy may preserve useful indicators, while premature cleanup can remove information about the attacker’s access and the malware’s drop mechanism.

Evidence or symptom	What it may indicate	Safe action
Malicious document in an email	Macro-based or script-assisted delivery	Preserve the message and attachment; do not enable content
JavaScript, archive, or executable in Downloads	User-assisted downloader execution	Record timestamps and scan from a trusted environment
New scheduled task or startup entry	Persistence after initial execution	Photograph or export details before removal
Remote login before encryption	Stolen credentials or exposed remote service	Disable affected accounts and review authentication logs
Files encrypted on shared drives	Lateral movement or accessible network storage	Disconnect shares and inspect other endpoints

Removing the Locky components

Use a trusted, updated security product from a clean administrative account or a known-safe rescue environment. A full offline scan is preferable when possible because active ransomware can interfere with ordinary Windows processes. On Windows, Safe Mode may help prevent some startup components from launching, but it is not a substitute for professional analysis.

Remove detected droppers, downloaders, scheduled tasks, registry run entries, and other persistence mechanisms identified by reputable security software. Do not manually delete system files based on random filenames or online forum guesses. A mistaken deletion can make the operating system unstable without removing the actual threat.

For high-confidence cleanup, rebuild the operating system from verified installation media after preserving essential evidence. Change passwords from a separate clean device, beginning with email, administrator, cloud-storage, and remote-access accounts. Apply operating-system and application updates before reconnecting the computer to the network.

Assessing decryption and file recovery

A decryptor may exist for a specific Locky variant, but ransomware tools are variant-dependent and criminals may falsely label other malware as Locky. Identify the family and extension first, then consult reputable security vendors, law-enforcement resources, and recognized incident-response organizations. Avoid “free decryptors” that demand payment, request excessive permissions, or arrive through unofficial download pages.

Search for offline backups, version history, cloud snapshots, and unaffected copies on disconnected media. Restore only after the machine has been cleaned or rebuilt; otherwise, restored files may be encrypted again. Preserve a copy of encrypted files and ransom notes in case a legitimate recovery tool becomes available.

For practical recovery options when no decryptor is available, review this file recovery guidance. Recovery attempts should be performed on copies, never on the only remaining version of the data.

Reducing the chance of reinfection

Preventing another ransomware event requires attention to both user behavior and technical controls. Macro-enabled documents should not be trusted merely because they resemble invoices, resumes, or shipping forms. Organizations should also restrict script execution from temporary directories and monitor unusual encryption activity.

Useful defensive measures include:

• Keep offline or immutable backups and test restoration regularly.
• Disable unnecessary macros, script interpreters, and remote-access services.
• Require multi-factor authentication for email, VPN, cloud, and administrator accounts.
• Use endpoint protection with behavioral ransomware detection.
• Train users to report suspicious attachments instead of opening them.

Email gateways should inspect archives and block dangerous attachment types where appropriate. Network segmentation can limit the damage if one workstation becomes infected, while least-privilege accounts reduce the malware’s ability to reach shared resources.

Get help safely

If the original email, process chain, or account compromise is unclear, avoid repeated trial-and-error cleanup. Preserve the available evidence, isolate affected systems, and document every action taken. This helps a qualified technician determine whether the threat was removed and whether other devices remain exposed.

For guidance about a suspicious infection or the safest next step, contact Pc Malware Expert with relevant symptoms and non-sensitive details. Never include passwords, private keys, or confidential business documents in a support request.