Nedal is a worm that makes reference to Osama Bin Laden and the tragic events that took place in New York in September 11, 2001. In fact, the message that it uses to spread has the subject Osama Bin Laden Comes Back!.
Nedal spreads massively and quickly as, besides e-mail, it uses IRC chat as a means of transmission.
When the worm activates it is very easy to know it is present on the system as it displays several messages that refer to the Al Qaeda terrorist organization.
Once the attached file is run, Nedal carries out really destructive actions, including overwriting files with the following extensions: VBS, VBE, GIF, JPG, BMP, AVI, MP3, MPG, ZIP, CAB, MDB, XLS, LNK, DOC, TXT and RTF. Moreover, the worm is programmed to delete the contents of the Windows system directory.
Nedal also creates three files in the affected computer, one of which can damage files with an EXE extension.
Finally, programming bugs in the worm's code might prevent it from working properly in the infected computer.