System Security an executable file which primary purpose is to start a parasite or launch some of its components. Once executed, the 05643921.exe file runs a process that is responsible for the parasite's payload. 05643921.exe is a significant part of a dangerous threat, but it can also work on its own. DO NOT execute it!
The 05643921.exe file is installed and used by System
Security 2009.
The 05643921.exe file usually runs the same named process. This process silently works in background and performs harmful actions. It remains active while 05643921.exe is present in the system. Removing the file will immediately terminate a process and prevent it from running later. That is why you have to manually delete the 05643921.exe file. If you cannot erase it, consider using recommended spyware removers, which will get rid of 05643921.exe and associated parasites for you.
In some cases a presence of 05643921.exe does not mean that your system is infected. The file may actually belong to some fully legitimate applications and therefore must stay intact. If you are in doubt, please scan the 05643921.exe file using you regular spyware remover or antivirus program.