TrojanSpy:Win32/Lurk is installed by other malware, such as Exploit:SWF/CVE-2013-5330.A.
It is installed with a random file name in %TEMP%, for example, %TEMP%\218c.tmp. This file is usually deleted the next time your PC is rebooted.
The trojan tries to download a portable executable file from a remote server and injects it into a web browser process. We have seen it contact the following domain:
Analysis by Chun Feng
Alerts from your security software may be the only symptom.