Some viruses delete files, reformat the hard disk or cause other damage. Others only replicate themselves and may present text, video, or audio messages.
Antivirus software detects and eliminates known viruses.
THREAT #2: SPAM
SPAM is electronic junk email. The amount of spam has now reached 90 billion messages a day. Email addresses are collected from chat rooms, websites, newsgroups.
Danger level: Low
Prevalence: Extremely High
Worst case damage:
Spam can clog a personal mailbox, overload mail servers and impact network performance. Perhaps the real danger of spam is not so much in being a recipient of it as inadvertently becoming a transmitter of it. Spammers frequently take control of computers and use them to distribute spam. Once a user’s computer is compromised, their personal information may also be illegally acquired.
Prevention, detection and removal:
User systems may use spam filters to screen out email messages with suspect titles or from suspect persons, as well email messages from blocked senders.
THREAT #3: SPOOFING
Spoofing is an attack in which a person or program masquerades as another. A common tactic is to spoof a URL or website.
Danger level: High
Prevalence: Extremely High
Worst case damage:
Once personal information is acquired, spoofers may use a person’s details to make transactions or create fake accounts in a victim’s name. They can ruin the victims’ credit rating or even deny the victims access to their own accounts.
Prevention, detection and removal:
As spoofing rely on tricking users rather than advanced technology, the best way to handle these threats is through vigilance. Don’t open emails from unknown sources or click on links embedded in suspect messages.
THREAT #4: BLENDED THREAT
A blended threat is a threat that combines different malicious components, such as a worm, a Trojan horse and a virus. In this way, a blended threat uses multiple techniques to attack itself.
Danger level: Extremely high
Prevalence: Medium
Worst case damage:
See respective entries for worm, Trojan horse and virus.
Prevention, detection and removal:
See respective entries for worm, Trojan horse and virus.
THREAT #5: WORM
A computer worm is a self-replicating, malicious software program. Unlike a virus, it does not need to attach itself to an existing program or require user intervention to spread. It uses a network to send copies of itself to other computers on the network.
Danger level: Very High
Prevalence: Moderate
Worst case damage:
Worms can cause two types of damage:
- Damage to the network
- Payload
Prevention, detection and removal:
Since worms spread by exploiting vulnerabilities in operating systems, computers should be kept current with the latest security updates from operating system vendors.
To prevent infection, users need to be wary of opening unexpected emails and should not run attached files or programs.
