Meaning of the ThreatCon levels
The Symantec ThreatCon rating is a measurement of the global threat exposure, delivered as part of Symantec DeepSight Threat Management System.
We always see the Threatcon level indicator on the Symantec.com website as well as the Endpoint Protection Manager.
Following is the description for each one of the levels:
ThreatCon Level 1
This condition applies when there is no discernible network incident activity and no malicious code activity with a moderate or severe risk rating. Under these conditions, only a routine security posture, designed to defeat normal network threats, is warranted. Automated systems and alerting mechanisms should be used.
ThreatCon Level 2
This condition applies when knowledge or the expectation of attack activity is present, without specific events occurring or when malicious code reaches a moderate risk rating. Under this condition, a careful examination of vulnerable and exposed systems is appropriate, security applications should be updated with new signatures and/or rules as soon as they become available and careful monitoring of logs is recommended. Changes to the security infrastructure are not required.
ThreatCon Level 3
This condition applies when an isolated threat to the computing infrastructure is currently underway or when malicious code reaches a severe risk rating. Under this condition, increased monitoring is necessary, security applications should be updated with new signatures and/or rules as soon as they become available and redeployment and reconfiguration of security systems is recommended. People should be able to maintain this posture for a few weeks at a time, as threats come and go.
ThreatCon Level 4
This condition applies when extreme global network incident activity is in progress. Implementation of measures in this Threat Condition for more than a short period probably will create hardship and affect the normal operations of network infrastructure.
To see the current level of Threatcon you can always visit the website: http://www.symantec.com/security_response/threatconlearn.jsp