Three people were recently arrested in Japan in relation to death threats being posted online and sent through email. However, once a particular malware infection was found on each suspect's computer, all three were released without charge.
Automatically sending threats from your PC, this particularly bloody-minded piece of malware has been blamed for a number of serious threats.
According to Symantec's analysis, these include a government-posted website message stating the user would commit mass murder, threats to blow up famous shrines, an email sent to an airline threatening to bomb aircraft and warnings to a kindergarten that hosted a child from a royal family.
Analysis of the malware has found that a sabotaged computer can be controlled through a remote location -- a common component of such infections. Through this control, the creator is able to make threats on behalf of the infected user's PC.
Coding strings include Japanese characters so it is likely the creator has a good or native understanding of the Japanese language. The only file discovered in connection to this infection is called iesys.exe, although others could exist.
Police are currently investigating the connection between threats and the malware, which has been named Backdoor.Rabasheeta. Several variants have been found, but all have been linked to accessing a single malicious website. Symantec says that due to this, the infection rate is probably very limited.
In order to avoid becoming infected, you should double-check the source of any downloaded software and keep your computer up-to-date. In addition, the anti-virus firm has released a free scanner for those not using their software.