It appears that AVG and Avast are incorrectly identifying some Ftax pdfs as malicious (reporting code JS:Pdfka-gen [Expl]).
Below is a brief description of the situation followed by steps you may wish to take to continue using Ftax.
We routinely scan all our files internally and have identified no problems.
We have submitted affected files for further scans to http://www.virustotal.com (which is owned by google’s parent company). This site aggregates the results of a wide range of different virus checkers and showed that only very small number of the 62 virus checkers it uses, identify the problem.
An example can be seen here:
We reported samples to the affected vendors as false positives. One of the vendors has already responded stating that the detection was incorrect (AVG) and that they will be updating their software as a matter of urgency. We expect the others to follow suit.
If you are affected, and you wish to stop the behaviour, you can exclude specific websites and files from being scanned.
For example, AVG users
For example, Avast users
https://support.avast.com/en-gb/article/Antivirus-scan-exclusions/
We would also encourage you to add the pdf file to your Quarantine/Virus Chest and submit it as a false positive to AVG/Avast Threat Labs from there
For example, AVG users
https://support.avg.com/SupportArticleView?l=en&urlName=Use-AVG-Quarantine&supportType=home
For example, Avast users