Other user John Pickles posting (https://support.avg.com/answers?id=906b0000000DiHXAA0).
AVG Guru
Like many others, yesterday I found that AVG on my MacBook Air was finding the JS:Nimbda-B threat, but AVG could not quarantine or delete the threat. Advice to clear the cache on my machine was followed but this did not fix the issue and the threat remained. I was re-assured over on the Apple Support Forums that this was a windows malware and a possible false positive, but the OCD in me didn't like the fact that AVG was still showing this as a threat. Then I had an epiphany. Yesterday, I mistakenly opened an email that had made its way past spam filters. Although I didn't specifically open the attachment, the email opened in the preview pane. Although I deleted the email I wondered if that could have been the source of the 'infection'. Out of interest, I ran AVG Cleaner and cleaned the downloaded email cache. After completion, I rebooted and ran AVG Anti Virus and it came back clear. And has remained clear on subsequent scans. I've no idea if this was just a coincidence and that AVG have fixed the issue or that I accidentally found the 'fix' by default, but it seems to have worked for me. Might be worth a try if you are struggling to get rid of JS:Nimbda-B.
What does your reply "Other user John Pickles posting" mean Alan Binch? The link you provide was indeed to a post by me. AVG provided me me with no answers, and I came across apssible solution myself, so I posted it as a new thread in the hope that it may assist other users suffering the same thing. Isn't that what support communities are all about?