W32/Karab-A is a USB aware worm.
W32/Karab-A may display a picture of Barack Obama on your computer.
When W32/Karab-A infects it will copy itself to many areas on the system. Folders will have a file created in them with the name "<Folder Name> .exe" and "readme.txt .exe" (typically ~90 spaces).
W32/Karab-A will also create:
Autorun.inf
Sandisk.exe
Bootsect.dll
"readme.txt .exe"