This indicates an attack attempt against a Buffer Overflow vulnerability in Mini-stream Software Products.
The vulnerability is caused by an error when the software handles a maliciously crafted "pls" file. As a result, a remote attacker can exploit this to execute arbitrary code within the context of the application.
Mini-stream Software Shadow Stream Recorder 3.0.1 7
Mini-stream Software Mini-streamRipper 3.0.1 .1
Mini-stream Software Mini-stream RM-MP3 Converter 3.0 .7
Mini-stream Software ASX to MP3 Converter 3.0 .7
System Compromise: Remote attackers can gain control of vulnerable systems
Currently we are not aware of any vendor supplied patches for this issue.