In the File Summary Info, it changes Author to "Opic", Title to "WM97/Caligula Infection", Subject to "A Study In Espionage Enabled Viruses.", Comments to "The Best Security Is Knowing The Other Guy Hasn't Got Any.", and Keywords to " | Caligula | Opic | CodeBreakers | "
It steals PGP secret keys and sends them to an FTP site over the Internet. PGP keys are protected by a passphrase. There are no known weaknesses in the encryption of the PGP Secret Key and this virus does not record keystrokes. If a person has a copy of your PGP key, the only thing he could try is a "brute force" attack where he tries every possible key. Someone using a word in the dictionary as a passphrase could have their key cracked within seconds. A long passphrase with uppercase, lowercase, numbers and punctuation could take millions of years. The FTP site where the keys were supposed to be sent to no longer allows anonymous logins so keys currently cannot be stolen by this virus. If there are any keys that were stolen, and they were cracked, someone could read secret messages or impersonate the person they were stolen from.
In the 31st of any month it displays:
Information about macro viruses.
MVK 97 can remove Caligula and other Word 97 viruses automatically.