Urgent Detection System is an original technology of spam detection developed and supported by Kaspersky Lab. It is based on the following principles:
1. A message being analyzed is used to select a collection of properties, which can be used to identify the message. The set of properties may include header information, text fragments and other information about the message being processed.
2. Filtration server uses the properties thus collected to generate a small UDS request and sends it to one of UDS servers of Kaspersky Lab. Since the product does not transmit to external servers any data that could allow viewing the recipients or the text of the processed mail, the use of this method does not pose any risk to the safety or confidentiality of your information.
3. The UDS server checks the received request against a database of known spam. If the request matches a known spam sample, a message will be sent to the filtration server informing that the e-mail is very likely to be spam. The information will be taken into account during assignment of a certain status to e-mail.
The UDS technology allows filtering of known spam before updates to the content filtration databases become available.
A filtration server interacts with UDS servers of Kaspersky Lab via UDP using port 7060 for communication. In order to use UDS, a filtration server must be able to establish outgoing connections through that port.
Information about available UDS servers is added to the content filtration databases. The choice of an individual UDS to be used for message analysis is performed automatically on the basis of the response time of accessible UDS servers.