LSASS is code designed for trying to exploit the LSASS vulnerability in Windows XP/2000 computers.
Some worms, like variants of Korgo.A, Sasser.A, Bobax.A and Gaobot, spread through the Internet. In order to do so, they generate several random IP addresses. Then, these worms send LSASS to these IP addresses.
If the targeted computer is not properly updated, when it receives LSASS, these worms will be downloaded and executed.
Another possible scenario would be the creation of a program that would scan IP addresses. This program should detect the vulnerable IPs in order to install other malware, such as Trojans or backdoors, in the targeted computers.
Panda Security detects the code necessary for attempting to exploit the LSASS vulnerability as LSASS, thus warning users on a network traffic increase associated to this threat and preventing them from being affected.
If you have a Windows XP/2000 computer, it is highly recommendable that you download the security patch from Microsoft's web site, by clicking here.