Yes, new filename extensions and files that no longer open could indicate ransomware. However, those symptoms alone do not confirm an attack; a ransom note, payment demand, or technical investigation is needed. Ransomware is malicious software that blocks access to files, systems, or networks and demands payment. Severe versions can encrypt files on local, attached, and networked drives.
Table of Contents
- What do the changed extensions mean?
- What should I do immediately?
- Can I restore my files from backup?
- Should I pay the ransom?
What do the changed extensions mean?
An unfamiliar extension can be a visible sign that ransomware has encrypted a file. For example, Play ransomware adds `.PLAY` to encrypted filenames and leaves a `ReadMe.txt` ransom note, according to a CISA, FBI, and ACSC cybersecurity advisory. The extension does not identify the cause by itself.
Look for a new text file, desktop message, or other notice containing payment instructions, an attacker email address, or a web address. Ransomware messages commonly demand cryptocurrency. Attackers may also threaten to publish stolen information, according to the UK National Cyber Security Centre.
What should I do immediately?
Treat the device as potentially infected until someone can investigate it. The priority is limiting access to other devices and storage locations. The NCSC advises immediately disconnecting affected computers, laptops, and tablets from wired, wireless, and mobile networks to help limit a suspected ransomware attack.
- Disconnect its Ethernet cable.
- Turn off its Wi-Fi connection.
- Disconnect it from mobile networks.
- Isolate other computers showing the same symptoms.
- Record the new extension and retain any ransom note or payment instructions.
Can I restore my files from backup?
Do not begin restoring files simply because a backup exists. Ransomware may already have reached a backup, and restoring onto an infected device can undermine recovery. Confirm that both the backup and the destination device are clean before restoration.
This may require technical investigation, especially when attached or networked drives also contain files with the unfamiliar extension. Keep the suspected infection isolated while recovery is assessed. A clean backup is useful only when the device receiving its files is also clean.
Should I pay the ransom?
Payment is not a dependable recovery method. The FBI says paying does not guarantee that attackers will return the data, while the NCSC warns that a victim's computer may remain infected or be targeted again.
U.S. victims can file a complaint with the FBI's internet Crime Complaint Center. Preserve these details for the report: The FBI's ransomware guidance specifically requests these indicators because they can help document and investigate the incident.
- The changed filename extension
- Any identified ransomware variant name
- The ransom note
- Cryptocurrency addresses
- Attacker email addresses or web addresses
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