Cyber threats
CYBERTHREATS in PC and Smartphones
Cyber threats: denial-of-service attacks, worms, viruses, and Trojan horses
Objective no 1.
Identify the different types of cyber threats in personal computer and smartphones.
DENIAL-OF-SERVICE ATTACKS A denial-of-service (DoS) attack, or distributed denial-of-service (DDoS) attack, consists of making repeated requests of a computer system or network, thereby overloading it and denying legitimate users access to it. Because computers are limited in the number of user requests they can handle at any given time, a DoS onslaught will tie them up with fraudulent requests that cause them to shut down. The assault may come from a single computer or from hundreds or thousands of computers that have been taken over by those intending harm.
WORMS Worms, viruses, and Trojan horses are three forms of malware, or malicious software, which attack computer systems. The latest Symantec Internet Security Threat Report identified over 1.6 million instances of “malicious code” (worms and viruses) in 2008, a 165% increase over 2007. A worm is a program that copies itself repeatedly into a computer’s memory or onto a disk drive. Sometimes it will copy itself so often it will cause a computer to crash. Among some famous worms are Code Red, Nimda, Klez, Sasser, Bagle, Blaster, Sobig, and Melissa. The 2002 worm Klez, dubbed the most common worm ever, spread its damage through Microsoft products by being inside email attachments or part of email messages themselves, so that merely opening an infected message could infect a computer running Outlook or Outlook Express. The Sasser worm was estimated to account for 26% of all virus infections in the first half of 2004. Incredibly, one person, Sven Jaschan, 18, who admitted programming the Sasser and other worms and who was arrested in Germany in May 2004, was responsible for 70% of the virus infections in the early part of that year.
In 2008–2009, a worm known as Conficker or Downadup, spread through
Cyber threats: denial-of-service attacks, worms, viruses, and Trojan horses
Objective no 1.
Identify the different types of cyber threats in personal computer and smartphones.
DENIAL-OF-SERVICE ATTACKS A denial-of-service (DoS) attack, or distributed denial-of-service (DDoS) attack, consists of making repeated requests of a computer system or network, thereby overloading it and denying legitimate users access to it. Because computers are limited in the number of user requests they can handle at any given time, a DoS onslaught will tie them up with fraudulent requests that cause them to shut down. The assault may come from a single computer or from hundreds or thousands of computers that have been taken over by those intending harm.
WORMS Worms, viruses, and Trojan horses are three forms of malware, or malicious software, which attack computer systems. The latest Symantec Internet Security Threat Report identified over 1.6 million instances of “malicious code” (worms and viruses) in 2008, a 165% increase over 2007. A worm is a program that copies itself repeatedly into a computer’s memory or onto a disk drive. Sometimes it will copy itself so often it will cause a computer to crash. Among some famous worms are Code Red, Nimda, Klez, Sasser, Bagle, Blaster, Sobig, and Melissa. The 2002 worm Klez, dubbed the most common worm ever, spread its damage through Microsoft products by being inside email attachments or part of email messages themselves, so that merely opening an infected message could infect a computer running Outlook or Outlook Express. The Sasser worm was estimated to account for 26% of all virus infections in the first half of 2004. Incredibly, one person, Sven Jaschan, 18, who admitted programming the Sasser and other worms and who was arrested in Germany in May 2004, was responsible for 70% of the virus infections in the early part of that year.
In 2008–2009, a worm known as Conficker or Downadup, spread through