How Does Malware Get In?

E-mail

E-mail is the transport mechanism of choice for many malware attacks.

Phishing

Phishing attacks try to trick people into revealing personal details such as credit card numbers or other financial or personal information. Although these attacks are rarely used to deliver malware, they are a major security concern because of the information that may be disclosed.

Removable media

This threat includes floppy disks, CD-ROM or DVD-ROM discs, Zip drives, USB drives, and memory (media) cards, such as those used in digital cameras and mobile devices.

Internet downloads

Malware can be downloaded directly from Internet Web sites such as social networking sites.

Instant messaging

Most instant messaging programs let users share files with members of their contact list, which provides a means for malware to spread. In addition, a number of malware attacks have targeted these programs directly.

Peer-to-peer (P2P) networks

To start file sharing, the user first installs a client component of the P2P program through an approved network port, such as port 80. Numerous P2P programs are readily available on the Internet.

File shares

A computer that is configured to allow files to be shared through a network share provides another transport mechanism for malicious code.

Rogue Web sites

Malicious Web site developers can use the features of a Web site to attempt to distribute malware or inappropriate material.

Remote exploit

Malware might attempt to exploit a particular vulnerability in a service or application to replicate itself. Internet worms often use this technique.

Network scanning

Malware writers use this mechanism to scan networks for vulnerable computers that have open ports or to randomly attack IP addresses.

Dictionary attack

Malware writers use this method of guessing a user's password by trying every word in the dictionary until they are successful.