You can find some tests on the internet, such as the Clementi comparatives of antivirus software:
The testers switch constantly between regular tests and retrospective tests.
However, the validity of such test scenarios is not that high because they use three-month-old engines to scan the newest forms of malware. All the producers of antivirus software update their engines regularly. However, malware authors have since become very quick at adapting their malefic code even faster than the year before.