Attachment detection by Cyren Premium AntiVirus

, , , ,
< zurück

The Cyren Premium AntiVirus scanner is part of the Malware Scanner action and can be used if NoSpamProxy Protection is licensed. Cyren Premium AntiVirus checks attachments that are attached to an email. In doing so, it carries out two basic checks:

  • Local checks against definitions
    • The definitions are regularly downloaded from the Cyren servers. In case of access problems to the Cyren servers, the definitions must not be older than two days.
    • During the check, the attachment is placed in the directory C:\ProgramData\Net at Work Mail Gateway\Cyren\Temp, checked and deleted again.
  • Live checks – Zero Hour Protection
    • Check for conspicuous attachments in the recent past. A hash value is generated and sent to Cyren, which then sends a response with the corresponding classification by Cyren.

Unlike with the Cyren AntiSpam filter, the NoSpamProxy support has no way of influencing this behaviour in the case of a misclassification.
In the case of misclassifications – i.e. false positives or false negatives – the sender or the recipient of the email must always contact Cyren and have this corrected accordingly.

A description of the process can be found on the respective Cyren support page.

In case of local problems or missing definitions, please refer to the Knowledge Base article Cyren Engines – Troubleshooting

Note

To ensure parallel operation with other locally installed virus scanners on the gateway role, please refer to the Knowledge Base article How to configure on-access virus scanners and define the exceptions as described!

Further information