Cyber-criminals use different types of attack vectors
and malware to compromise networks. The five most
typical types are viruses, worms, Trojans, spyware and
Computer viruses were originally spread through the
sharing of infected floppy disks. As technology evolved,
so too did the distribution method. Today, viruses are
commonly spread through file sharing, web downloads
and email attachments.
Computer worms have existed since the late 1980s but
were not prevalent until networking infrastructures
within organizations became common. Unlike computer
viruses, worms can crawl through networks without any
Trojans are designed specifically to extract sensitive data
from the network. Many types of Trojans will take control
of the infected system, opening up a back door for an
attacker to access later. Trojans are often used in the
creation of botnets.
Spyware is not typically malicious in nature, but it is a
major nuisance because it often infects web browsers,
making them nearly inoperable. At times, spyware has
been disguised as a legitimate application, providing the
user with some benefit while secretly recording behavior
and usage patterns.
Ransomware is an attack that often encrypts the files on
an endpoint or server demanding the end-user to pay a
ransom in bitcoin to receive the encryption key. When
it spreads to business-critical systems, the cost of the
ransom can swell to hundreds of thousands of dollars.