Alaeda is a non-resident virus. It infects systems running Linux, and is written in Assembly. It infects .ELF format files in the current directory.
When infecting, the virus modifies the entry point of the original file, passing control to the infection routine. It then modifies the file's .ELF header. Before infecting, the virus checks to see if the computer is vulnerable. The .TXT part of the file must also be the minimum size to infect.
The virus writes its body to the .TXT section. The size of the file will not change, making it hard to tell if files are infected.
Once the virus body has delivered its payload, control is returned to the program code.
If a file is already infected, the virus will not re-infect the file.
The following strings can be found in infected files:
AL-QAEDA 1-02-032 With help of Allah I will die for Allah