I'm trying to use Microsoft Baseline Security Analyser (MBSA) as part of my regular computer health checks. Unfortunately the security updates phase of MBSA operation is being blocked by Avast.
Has anyone else experienced this issue (which may be related to
http://forum.avast.com/index.php?topic=86625.0), or does anyone know of a solution other than disabling Avast?
InformationOperating system: Windows Vista Home Premium 32-bit (SP2).
Avast Free Antivirus: 7.0.1474 and 9.0.2006.
MBSA: Version 2.2.
Steps to reproduce:
- Have Avast running normally with all shields running.
- Start MBSA and select its options to both update and scan.
- Click the MBSA "start scan" button.
Behaviour:
- Expected: MBSA to download and apply its security updates, followed by running its scan.
- Actual: MBSA hangs at the updates phase. Avast uses 90-100% CPU on one core, observed with Process Explorer from Sysinternals, for a few minutes, then relaxes. TCPview shows that network activity on the MBSA TCP port (via Avast's 12080 port) has ceased after some initial reading and writing.
- Impact: MBSA cannot be used when Avast is running normally.
Additional Info:
- Repeating the procedure with Avast's network shield stopped, has no effect.
- Repeating the procedure with Avast's web shield stopped, allows MBSA to operate normally, successfully downloading updates and performing its scan.
- Repeating the procedure after completely stopping the Avast Service (avastsvc.exe) also allows MBSA to operate normally, successfully downloading updates and performing its scan.
- Starting the Avast service (and thereby starting its network and web shields), then repeating the MBSA procedure, results in the updates phase hanging again, with the same symptoms: high Avast CPU usage and frozen TCP traffic.
