Deceptive filenames like "update_v2.0.rar" or random numeric strings are often used in phishing emails to deliver Trojans or scripts.
Some ransomware families, like VoidCrypt , append unique ID numbers and the ".rar" extension to your original files after encrypting them (e.g., document.pdf.[ID-52421].rar ).
If this was an unsolicited email attachment or a download from an "unofficial" site, it is highly likely to be a threat.
Upload the file to VirusTotal to scan it against dozens of antivirus engines simultaneously.
If you must interact with RAR archives, always use official, updated software: How to Open RAR Files on Windows, Mac, and Mobile - Avast
The identifier does not refer to a standard software version or a widely known benign file. In many technical contexts, strings of digits paired with a RAR extension are associated with automated malware campaigns or ransomware variants .