Researchers at SophosLabs have released detection for Troj/Small-EJA.
As the name implies, Troj/Small-EJA has a very small filesize in comparison to a lot of malware in the wild.
Being small however does not mean this malware cannot wreak havoc on a users computer.
Troj/Small-EAJ is designed to download other malware from the internet and execute it without the users permission.
Weighing in at just over 1 kilobyte in size it is small enough to have downloaded to your computer before you have had the chance to think things through.
Also, if the malware author wished to spam out his creation, which is very common these days, he could do so at a much faster rate, and then let the infected computer do the majority of the downloading.
If successful Troj/Small-EJA will download and run Troj/Rustok-R.
Troj/Rustok-R will create and execute a rootkit which is designed to stealth itself and potentially other malware Troj/Rustok-R may download and execute.
This all goes to show, its not the size of the file that counts :).