Carioca Virus

Virus Name: Carioca Aliases: V Status: Rare Discovery: November, 1990 Symptoms: TSR; .COM growth Origin: Eff Length: 951 Bytes Type Code: PRsC - Parasitic Resident .COM Infector Detection Method: ViruScan, AVTK, F-Prot, NAV, Sweep, IBMAV, NAVDX, VAlert, PCScan, ChAV, NShld, LProt, Sweep/N, Innoc, NProt, AVTK/N, NAV/N, IBMAV/N Removal Instructions: Delete infected files General Comments: The Carioca virus was submitted in November, 1990. This virus is a memory resident infector of .COM files, it does not infect COMMAND.COM. The first time a program infected with the Carioca virus is executed, the virus will install itself memory resident as a 1,280 byte low system memory TSR. Interrupt 21 will be hooked by the virus. The system's available free memory will decrease by 1,312 bytes. After the virus is memory resident, any .COM file executed (with the exception of COMMAND.COM) will become infected with the Carioca virus. Infected .COM files will show an increase in size of 951 bytes with the virus being located at the end of the infected file. Infected files will have the following hex character string located at the very end of the file: "2EFF1E1A010203CD21". It is unknown if Carioca contains any damage potential. Known variant(s) of Carioca are: Carioca-B: Received in November, 1993, Carioca-B is a very minor variant which has been altered to avoid being detected by a particular anti-viral utility. It is not believed to be in the public domain. Origin: Unknown November, 1993.