Malware Using Right to Left Override Unicode
 

The new generation of bad file name to deceive the user to open an EXE or any extension by showing a txt, pdf or anything else extensions it uses by new virus, worm etc. files...
It caused by using a Unicode character that reveres string... :p

http://www.f-secure.com/weblog/archives/00002219.html

@SinaDiR: This technique had been around for several yrs actually. In the past, you can even implement it for emails as well.

BR,
[ Gunther ]