A SYSTEM USING IM SCREENER IN A CLIENT COMPUTER TO MONITOR BAD REPUTATION WEB SITES IN OUTGOING MESSAGES TO PREVENT PROPAGATION OF IM ATTACKS

In one embodiment, an instant messaging screener is configured to (a) intercept an instant message destined to a user account, (b) parse the instant message to identify any universal resource locators (URLs) in the instant message, (c) check any URLs identified in the instant message against a URL ratings database to generate reputation data; and (d) perform a protective action if the reputation data indicates a bad reputation. In another embodiment, the instant messaging screener is configured to (a) monitor outgoing instant messages to identify any universal resource locators (URLs) therein which are associated with bad reputation web sites, (b) track historical results of said monitoring, and (c) determining whether said identified instant are being sent to all members, or a substantial portion of the members, of a contact list for a user account. Other embodiments, aspects and features are also disclosed.