Increased false positive rate caused by file-based virus scanner

We are currently experiencing an increased number of false positive reports in NoSpamProxy’s Malware Scan feature. Here you will find our recommendations for action.

The reports are caused by the use of Windows Defender in cases where it is configured and used as a local virus scanner. Currently, mainly PDF and Excel documents are detected and rejected by Windows Defender.

We currently recommend deactivating Windows Defender if you use it as a file-based virus scanner. However, we cannot say when the problem will be solved, as we have no influence on Windows Defender.

In addition, please note the necessary exceptions for local virus scanners, which must always be set, regardless of whether Windows Defender is used as an additional virus scanner in NoSpamProxy or not.

Please also note that the necessary exceptions have changed with the introduction of version 14.0.5. Make sure that you have implemented the adapted changes in your environment after the update. All relevant information on this can be found in our documentation.