More on the RSTP vulnerability from Quicktime. Countermeasures include disabling Quicktime and iTunes until the problem is patched (likely v7.4), blocking RSTP at the gateway (TCP 554 and a range of UDP ports in 6000's), IDS detection of RSTP. Note- files are vulnerable too, so just blocking egress ports is probably not enough as any installed malware will probably use port 80 to egress. Best to disable the applications via the Registry (or uninstalling) until the patches are available as these exploits are almost certainly out there now.