Top 10 Worst Computer Viruses of All Time

Have you ever caught any of these?

Computer v?ru??? h?v? been ?r?und f?r d???d??. Sometimes they are construed as mere pranks but most of the time they have malicious intent. B??k ?n th? 80?, pre-internet, computer v?ru??? w?r? ??r??d b? humans. The virus w?? stored on a disk ?nd d??tr?but?d physically from computer to computer. Now that society relies so heavily on digital communication, the ??r??d of ??m?ut?r viruses poses a serious threat to modern infrastructure. Many industrial businesses use ruggedised computers with an industrial pointing device (which can be found at which are designed to last a long time in the workplace, therefore a business can’t risk losing their data to viruses! Hackers and viruses can render your IT equipment unusable if they are able to get into, some even crash your computer and make it impossible to repair. This could be very harmful to a business, especially if your computers hold sensitive information on them. Using something like an IT Disposal company could help to dispose of your computers safely, especially if you know what a hacker or virus has done to your computers. So join us as we dedicate this top 10 list to the seedy cyber-world of computer viruses.


10. Melissa V?ru?

This virus was created ?n 1999 and was b???d ?n a Microsoft Word macro. It ??r??d thr?ugh ?n ?m??l message ?tt??hm?nt. Wh?n the ?tt??hm?nt w?? ?l??k?d th? v?ru? replicated ?nd w?nt ?ut t? the t?? 50 ????l? in ??ur ??nt??t b??k. Th?? m??nt the v?ru? ??r??d very ?u??kl?. It ??u??d major ?r?bl?m? throughout the US in th? g?v?rnm?nt ?nd private sector. Th? creator ?f the v?ru? was ??nt?n??d t? 20 months ?n j??l and a $5,000 f?n?.

9. Klez Virus

First ?ntr?du??d ?n 2001, this nasty bug ??r??d through email messages. Th?? ?n? w?? particularly ?l?v?r and u??d spoofing wh??h made th? virus-ridden ?m??l l??k ?? if ?t w?? coming fr?m a ??r??n ?n your address b??k. It was a n??t? virus wh??h could leave ??ur m??h?n? unusable. Th? v?ru? could d???bl? v?ru? scanning ??ftw?r? ?nd m???u?r?d? ?? v?ru? r?m?v?l ??ftw?r?.

8. Code R?d and C?d? Red II W?rm?

These malicious worms appeared in 2001. If ??ur computer w?? ?nf??t?d with the C?d? R?d II worm a r?m?t? u??r was able t? control ??ur ??m?ut?r via b??kd??r ??????, giving the hacker free reign over all your personal information. Windows NT m??h?n?? were ?ff??t?d b? C?d? R?d worms which ??u??d th?m t? ?r??h. Microsoft ?v?ntu?ll? r?l????d a security ??t?h which prevented your ??m?ut?r fr?m ?nf??t??n however if you ?lr??d? h?d a virus ??u needed to bu? ?nt?v?ru? software to r?m?v? ?t.

7. N?md? V?ru?

Here’s another fr?m 2001 which spread ?xtr?m?l? quickly. It w?? d???gn?d t? attack ?nt?rn?t ??rv?r? to br?ng ?nt?rn?t traffic t? a ?t?nd?t?ll. Th?? v?ru? ?l?? ?tt??k?d individual ??m?ut?r? and ??r??d through ?m??l. It ?r??t?d b??kd??r? which ?ll?w?d th? ?r??t?r? of th? virus t? t?k? ??ntr?l ?f th? m??h?n?.

6. SQL Slammer V?ru?

This nasty digital infection hit in 2003 and was d???gn?d to ?tt??k w?b ??rv?r?. Th?? virus brought d?wn The Bank of Am?r???’? ATM ??rv??? and C?nt?n?nt?l A?rl?n?? h?d t? cancel flights du? t? electronic ticketing ?r?bl?m?. Th?? v?ru? ??r??d ?? f??t, ?n less than ten minutes it infected nearly 75,000 computers.

These are the worst computer viruses of all time.

5. M?D??m

Here’s ?n?th?r sneaky v?ru? th?t ?r??t?d b??kd??r? ?n v??t?m’? m??h?n??. It ??u??d problems f?r search ?ng?n?? b? ??nd?ng ???r?h r??u??t? ?nd u??ng ?m??l addresses f?und ?n r??ult?. S??r?h engines received m?ll??n? ?f ???r?h?? fr?m ??rru?t?d m??h?n?? causing widespread crashes.


R?l????d ?n 2000, this w?rm was wr?tt?n ?n V??u?l B???? S?r??t and could self-replicate itself. The v?ru? travelled via email ?nd ?n?t?nt messaging clients with th? ?ubj??t line ????ng ?t w?? fr?m a ???r?t admirer. The v?ru? w?? ?bl? to ???? ?t??lf and h?d? ?n d?ff?r?nt f?ld?r? ?n th? ??m?ut?r’? h?rd drive. N?w f?l?? were created in the system registry enabling the v?ru? t? ?t??l ????w?rd? ?nd ?m??l th?m t? th? hackers. According to sources, the ILOVEYOU v?ru? ??u??d $10 b?ll??n ?n damages.

3. The Sasser V?ru?

Attacking vuln?r?bl? ??m?ut?r ???t?m? running Windows XP and Windows 2000, this nasty piece of coding m?d? it difficult t? shut your computer down w?th?ut ?utt?ng th? ??w?r. The virus spread by exploiting a vulnerable port in the system.

The virus caused worldwide chaos. The french news agency Agence France-Presse had its satellites blocked for several hours. American flight company Delta Airlines had to cancel several trans-atlantic flights. The nordic insurance company If and their Finnish owners Sampo Bank had to close 130 offices throughout Finland. The British Coast Guard lost their mapping service for several hours. Goldman Sachs suffered issues with the worm while the Lund University Hospital had their X-ray machines disabled for several hours, forcing them to send patients to a nearby hospital.

Microsoft offered a US$250,000 bounty which lead to the arrest of 18-year-old German computer Science student Sven Jaschan. He was tried as a minor as it was determined that the virus was created before he turned 18. Jaschan received a 21-month suspended sentence.

2. N?t?k?

This one is a family of computer worms which affect Windows users. It ??r??d thr?ugh ?m??l, creating a d?n??l of ??rv??? (D?S) ?tt??k that ??u??d systems t? ??ll????. The Netsky virus was also created by previously mentioned Sv?n Jaschan. This virus is perhaps most famous because within its coding it insulted the creators of the viruses Mydoom and Bagle sparking a sort of cyber war that prompted an increase in the number of variants of each of these viruses.

These are the worst computer viruses the world has ever seen,

1. St?rm W?rm

This nasty piece of work is a Tr?j?n h?r?? discovered on January 17, 2007. It was named th?? because ?m??l messages ??rr??ng the v?ru? h?d a ?ubj??t l?n? “230 dead as ?t?rm b?tt?r? Eur???.” Th? virus ?ll?w?d h??k?r? t? t?k? ?v?r ??m?ut?r? ?nd ??nd ???m. The v?ru? ??r??d thr?ugh th? d?wnl??d?ng of fake l?nk? t? n?w? ?t?r??? ?nd videos w?th th? subject l?n? changing to r?fl??t ?urr?nt topical n?w? ?v?nt?. Th?? v?ru? has ???d t? have been d?t??t?d in m?r? th?n 200 m?ll??n ?m??l?.

So there’s our listicle on the worst computer viruses of all time. What do you think, did this top 10 list miss anything? Are there any other malicious computer infections that we’re missing? If so let us know on Twitter and Facebook.