A wiper is a piece of malware that wipes off the user's hard disk.
A piece of malware referred to as "Wiper" was allegedly used in attacks against Iranian oil companies. In 2012, the International Telecommunication Union supplied Kaspersky Labs with hard drives allegedly damaged by Wiper for analysis. While a sample of the alleged malware could not be found, Kaspersky discovered traces of a separate piece of malware known as Flame.
The Shamoon malware contained a disk wiping mechanism; it was employed in 2012 and 2016 malware attacks targeting Saudi energy companies, and utilized a commercial direct drive access driver known as RawDisk. The original variant overwrote files with portions of an image of a burning U.S. flag. The 2016 variant was nearly identical, except using an image of the body of Alan Kurdi instead.
A wiping component was used as part of the malware employed by the Lazarus Group—a cybercrime group with alleged ties to North Korea, during the 2013 South Korea cyberattack, and the 2014 Sony Pictures hack. The Sony hack also utilized RawDisk.
In 2017, computers in several countries—most prominently Ukraine, were infected by a variant of the Petya ransomware, which had been modified to effectively act as a wiper. The malware infects the master boot record with a payload that encrypts the internal file table of the NTFS file system. Although it still demanded a ransom, it was found that the code had been significantly modified so that the payload could not actually revert its changes if the ransom were successfully paid.