What is the term used for the unique identifier that antivirus software uses to recognize viruses?

What is the term used for the unique identifier that antivirus software uses to recognize viruses?

• A. Signature
• B. Checksum
• C. Heuristic
• D. Firewall rule

Answer: (A)

Antivirus software uses a signature—the unique pattern of bytes or metadata that identifies a specific virus. The scanner looks through files and compares their contents to a database of known signatures; if a match is found, that file is flagged as malicious. Signatures are derived from the virus’s actual code fragments and are updated as new threats appear, making this method fast and accurate for known malware. Other ideas don’t fit this purpose: a checksum is a hash used to check that a file hasn’t been altered, not to identify which virus is present; heuristics examine behavior to spot suspicious activity and can catch unknown threats, but they’re not a fixed identifier for a virus; firewall rules govern network traffic, not the recognition of malware inside files.

Antivirus software uses a signature—the unique pattern of bytes or metadata that identifies a specific virus. The scanner looks through files and compares their contents to a database of known signatures; if a match is found, that file is flagged as malicious. Signatures are derived from the virus’s actual code fragments and are updated as new threats appear, making this method fast and accurate for known malware.

Other ideas don’t fit this purpose: a checksum is a hash used to check that a file hasn’t been altered, not to identify which virus is present; heuristics examine behavior to spot suspicious activity and can catch unknown threats, but they’re not a fixed identifier for a virus; firewall rules govern network traffic, not the recognition of malware inside files.