John Norstad of Northwestern University this weekend released version 2.9 of his free anti-virus utility, Disinfectant. Version 2.9 detects the T4 virus, two strains of which were discovered in several locations around the world late last month.
The T4 virus can interfere with the booting process, either causing crashes during startup or preventing system extensions from loading properly. It masquerades as Disinfectant when attempting to infect files, in an apparent attempt to get around the "suspicious activity monitor" type of anti-virus utility. If you see a warning that "Disinfectant" is attempting to modify a file, and you are not using Disinfectant, it is a good indication that the T4 virus may be attacking your system.
Unfortunately, applications that have been infected with the T4 virus can not be repaired, so it is necessary to delete and replace any infected applications. Previously, Disinfectant had been able to repair virtually any infection. Some anti-virus authors prefer to recommend that users always replace, rather than repair, any infected files, but Norstad feels that it's more realistic to offer users the option of repairing files rather than expecting them to religiously replace applications. In this case, though, the option is not available.
The virus was embedded in two versions, 2.0 and 2.1, of the game GoMoku, which was distributed widely via online services, Internet FTP archives, and the comp.binaries.mac Usenet group. Users who have these versions of GoMoku should discard them and use Disinfectant 2.9, or another anti-virus utility released since the beginning of July, to scan all of their disks. The games were apparently distributed under a false name; the person whose name appears in the program's about box was completely uninvolved with the virus, and that name should not be used when referring to the virus.
Norstad took the opportunity in his release announcement to mention that three Cornell University students have been indicted on an assortment of felony and misdemeanor counts, including first-degree computer tampering, in connection with the release of the MBDF virus this spring. They are presently awaiting trial. Norstad hopes that this news will remind potential virus writers that computer viruses are taken seriously, and that writing them and releasing them is a crime that can, should, and will be punished under the law.