Specifications

Protecting Computers from Security Risks
5-3
Virus
A virus is a program that replicates. To do so, the virus needs to attach itself to other
program files and execute whenever the host program executes.
• ActiveX malicious code: Code that resides on Web pages that execute ActiveX™
controls
• Boot sector virus: A virus that infects the boot sector of a partition or a disk
• COM and EXE file infector: An executable program with .com or .exe extension
• Java malicious code: Operating system-independent virus code written or
embedded in Java™
• Macro virus: A virus encoded as an application macro and often included in a
document
• VBScript, JavaScript, or HTML virus: A virus that resides on Web pages and
downloads through a browser
• Worm: A self-contained program or set of programs able to spread functional
copies of itself or its segments to other computers, often through email
Test Virus
A test virus is an inert file that is detectable by virus scanning software. Use test viruses,
such as the EICAR test script, to verify that the antivirus installation scans properly.
Packer
Packers are compressed and/or encrypted Windows or Linux™ executable programs,
often a Trojan horse program. Compressing executables makes packers more difficult
for antivirus products to detect.
Probable Virus/Malware
Suspicious files that have some of the characteristics of virus/malware are categorized
under this virus/malware type. For details about probable virus/malware, see the
following page on the Trend Micro online Virus Encyclopedia:
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=POSSIBLE_V
IRUS