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

• For information on the detection by the Cyren AntiSpam Filter, please refer to the Knowledge Base article Recognition of emails by the Cyren AntiSpam filter.
• For information about detection by the Cyren IP Reputations filter, see Knowledge Base article Detection of IP addresses by the Cyren IP Reputation filter
• For information on detection by the Cyren URL classification service, see the Knowledge Base article How to influence URL classifications.
• Troubleshooting information for all Cyren services can be found in the Knowledge Base article Cyren Engines – Troubleshooting.

Configuring the CYREN Services for use with a Web Proxy

This article describes how to configure a proxy server for the CYREN services with the Protection module in all NoSpamProxy versions from version 9.2 onwards. To do this you have to download the files

• ctasd.conf
• ctipd.conf (additionally available from version 12.x)
• ctwsd.conf (additionally available as of version 13.x)

from the directory “C:\ProgramData\Net at Work Mail Gateway\CYREN\”.

The following section is responsible for this:

#   If you connect to the Internet through a proxy server, you
#   should uncomment the following parameters and assign appropriate
#   values.
#ProxyPort = 80
#ProxyServerAddress = myproxy
#ProxyAuth = NoAuth
#ProxyUserName = user@proxy
#ProxyPassword = 1234
#ProxyAccess = 1


If you are using a proxy server without authentication, remove the # character before the lines “ProxyPort”, “ProxyServerAddress”, “ProxyAuth” and “ProxyAccess”. Enter the corresponding port of your proxy server in ” ProxyPort”. Behind the entry “ProxyServerAddress” you configure either the IP address or the FQDN of your proxy server. For “ProxyAuth” leave the entry at “NoAuth”.

If you are using a proxy server with authentication, you must additionally configure the options “ProxyUserName” and “ProxyPassword”. Enter the corresponding logon information for “ProxyUserName” and “ProxyPassword”. Additionally, you must change the value “ProxyAuth” to “Basic”.

After you have saved the file, you must restart the services NoSpamProxy – CYREN Service (ctasd.conf), NoSpamProxy – CYREN IP Reputation Service (ctipd.conf) and NoSpamProxy – CYREN URL Categorization Service (ctwsd.conf) in order for the changes to take effect.

Note

In order for all Cyren services to function properly, unrestricted access to *.ctmail.com must be given. Also a virus scan on these connections must not be done, because the definitions for the Cyren Premium AntiVirus are downloaded there as well!

How to set the number of concurrent connections manually

This article describes how to change the number of outbound connections of the Gateway role.

The corresponding settings are specified in the file “Gateway Role.config” in “C:\ProgramData\Net at Work Mail Gateway\Configuration\” on the respective gateway role. To edit the file, first stop the gateway role.

Below the tag

<netatwork.nospamproxy.proxyconfiguration ... >

find the tag <queueConfiguration> and add the attributes maxConcurrentConnections="xx" and maxConcurrentConnectionsPerDomain="xx" to it. It should look like this:
<queueConfiguration maxConcurrentConnections="100" maxConcurrentConnectionsPerDomain="10" />

This limits the number of concurrent connections to 100, with a maximum of 10 concurrent connections allowed per domain.