Virus Name: Carioca
V Status: Rare
Discovery: November, 1990
Symptoms: TSR; .COM growth
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,
Removal Instructions: Delete infected files
The Carioca virus was submitted in November, 1990. This virus is a
memory resident infector of .COM files, it does not infect
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
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.