More likely is that Avast fixed their pattern file so it no longer generates a false positive with the pdf file and then your system's automatic update got the new pattern file, ran it and found no problem.
You can test for yourself by doing a binary file compare on a good and 'bad' copy of the files and see if there is, in fact, anything changed.
Remember that anti-virus programs are just software, not intelligence.
__________________
.
The great menace to progress is not ignorance but the illusion of knowledge - Daniel J. Boorstin
The takers get the honey, the givers sing the blues - Robin Trower, Too Rolling Stoned - 1974
|