Malware in the 80's and Malware in the 21st Century

Developing computer virus have been growing along side with the growth of computer technologies. The purpose, effect and technologies used in developing these viruses have varied greatly as the year of development. In this article we compare a popular virus designed in the 80's and the recent one designed in 2007.

Lehigh computer virus

Its is a file virus that was discovered in 1987 that affects command.com which is the filename of default DOS of Windows OS. Though the virus wasn’t traced  back to the originator but it was rather named after Lehigh University where it was first detected.

Methods of propagation

Lehigh spreads itself by infecting a DOS disk. If lehigh is running in the memory of a host computer and another DOS is inserted in the computer, lehigh detects the DOS disk and infect the command.com file.

Effects

Lehigh virus overwrites the boot sector of the OS and file allocation table, thereby making the computer unbootable on the next reboot or restart. And therefore the motive of the lehigh virus could be to make any infected device on bootable.

Technologies

Lehigh various was written in Assembly language.

Stuxnet

As opposed to other computer malwares which seeks to attack a users pc and cause damage or malfunction, stuxnet attacks Industrial Control Systems by attaching itself to the computers that hosts the Programmable logic for these ICS systems.

A computer worm probably designed by US/Israeli Government that targets programmable logic controls made by siemens. It was first discovered in 2008.

Method of propagation

Its spreads itself by infecting a usb flash drive attached to an infected computer. Its spreads itself across the computer network and seeking for a PLC designed by siemens to launch attack on.

Effects

Stuxnet attacks desired target is the PLC for centrifuges used in nuclear power plants. It causes the centrifuges to spin at great speed and thereby tear themselves apart. And most if not all of the attack on centrifuges in nuclear reactors are located in Iran(More than 50% of the overall infected computers all over the world is located in Iran). The worm also posses a rootkit capability thereby running itself on a victim's computer without any flag raised or user being aware of the changes in processes.

Technologies

As a typical code for programmable controllers, stuxnet is written in C and C++ and other programming languages. Some part of the code is available for public view https://github.com/Laurelai/decompile-dump/commit/2e113131800ca2152eb3b843e41823723ec5a673 .

Conclusion

The goal of a 19th century virus is mostly to destroy a users computer or cause it to malfunction is some way but the 20th century virus is usually financially or politically related. The designers of modern day viruses seeks to make money from them and in the case of stuxnet and other similar virus/worms, can be used in cyberwars and politically related actions.