User manual

Viruses and more
Avira Server Security - User Manual (Status: 16 Dec. 2013) 28
Pharming
Pharming is a manipulation of the host file of web browsers to divert enquiries to spoofed
websites. This is a further development of classic phishing. Pharming fraudsters operate
their own large server farms on which fake websites are stored. Pharming has established
itself as an umbrella term for various types of DNS attacks. In the case of a manipulation
of the host file, a specific manipulation of a system is carried out with the aid of a Trojan or
virus. The result is that the system can now only access fake websites, even if the correct
web address is entered.
Phishing
Phishing means angling for personal details of the Internet user. Phishers generally send
their victims apparently official letters such as emails that are intended to induce them to
reveal confidential information to the culprits in good faith, in particular user names and
passwords or PINs and TANs of online banking accounts. With the stolen access details,
the phishers can assume the identities of the victims and carry out transactions in their
name. What is clear is that: banks and insurance companies never ask for credit card
numbers, PINs, TANs or other access details by email, SMS or telephone.
Polymorph viruses
Polymorph viruses are the real masters of disguise. They change their own programming
codes - and are therefore very hard to detect.
Program viruses
A computer virus is a program that is capable of attaching itself to other programs after
being executed and cause an infection. Viruses multiply themselves unlike logic bombs
and Trojans. In contrast to a worm, a virus always requires a program as host, where the
virus deposits its virulent code. The program execution of the host itself is not changed as
a rule.
Rootkits
A rootkit is a collection of software tools that are installed after a computer system has
been infiltrated to conceal logins of the infiltrator, hide processes and record data -
generally speaking: to make themselves invisible. They attempt to update already installed
spy programs and reinstall deleted spyware.
Script viruses and worms
Such viruses are extremely easy to program and they can spread - if the required
technology is on hand - within a few hours via email round the globe.