Virus Name: Junkie
V Status: Common
Discovered: July, 1994
Symptoms: .COM & .EXE growth; MBR & Boot Sector altered;
decrease in total system & available free memory
Eff Length: 1,030 - 1,042 Bytes
Type Code: PRtCKBX - Parasitic Resident .COM, MBR, & Boot Sector Infector
Detection Method: F-Prot, AVTK, IBMAV, ViruScan, Sweep, NAV, NAVDX,
VAlert, PCScan, ChAV,
AVTK/N, Sweep/N, NShld, Innoc, IBMAV/N, NProt, NAV/N,
Removal Instructions: Delete infected files, Replace MBR, DOS SYS on system
The Junkie virus was received in July, 1994. It appears to be from
Sweden. Junkie is a memory resident multi-partite virus which
infects diskette boot sectors, the system hard disk master boot
sector (containing the partition table), and .COM files, including
COMMAND.COM. As of August, 1994, confirmed public domain infections
have been reported in the United States, Canada, Belgium,
The Netherlands, and Spain.
When the first Junkie infected program is executed, this virus will
infect the system hard disk master boot sector. The virus doesn't
become memory resident nor infect programs at this time. Later,
when the system is booted from the system hard disk, the Junkie
virus becomes memory resident at the top of system memory but below
the 640K DOS boundary, moving interrupt 12's return. Total system
and available free memory, as indicated by the DOS CHKDSK program, will
have decreased by 3,072 bytes. Interrupts 1C and 21 will be hooked
by the virus in memory.
Once the Junkie virus is memory resident, it will infect .COM
programs, including COMMAND.COM, when they are executed or opened for
any reason. Programs infected with the Junkie virus will have a file
length increase of 1,030 to 1,042 bytes with the virus being located
at the end of the file. The program's date and time in the DOS disk
directory listing will not be altered. The following text strings are
encrypted within the viral code in all Junkie infected programs:
"Dr White - Sweden 1994"
"Junkie Virus - Written in Malmo...M01D"
The Junkie virus infects diskette boot sectors when they are accessed.
The virus will write a copy of itself the last track of the diskette,
and then alter the boot sector to point to this code. On high density
5 1/4 inch diskettes, the viral code will be located on Cylinder 79,
Side 1, Sectors 8 and 9.
It is unknown what Junkie does besides replicate.