Patent ID: 8874649

Claim:
A system for determining a spammer, comprising: a session division apparatus configured to acquire short message events associated with a user and divide them into a plurality of sessions in terms of time, wherein division into a plurality of sessions comprises division into bulk sessions and normal sessions according to a sending behavior of the user, wherein, the bulk session is the duration of a behavior of sending short messages in bulk by the user, and the normal session is the duration of a behavior of sending short messages normally by the user, the division comprising in response to the rate of sending short messages by the user exceeding a preset rate r, marking the start of the bulk session, and in response to the rate of sending short messages by the user being lower than the preset rate r, marking the end of the bulk session, wherein the normal session is a partial period of the adjacent bulk sessions; a social network building and characteristic calculating apparatus configured to build a social network of the user in each of the sessions, and calculate at least one type of social network characteristic in each of the sessions, respectively; and a determination apparatus configured to determine whether the user is a spammer or not according to the social network characteristic by sampling the short message events sent to different receivers by the user to a token bucket; in response to arrivals of the short message events, supplying the token bucket with an increment T, and then consuming a predetermined number of tokens, wherein the increment T is the product of the time interval between two consecutive pieces of said short message events and the preset rate r; when the number of available tokens is smaller than 1, determining that the rate of sending short messages by the user exceeds the preset rate r; when it is determined that the rate of sending short messages is smaller than the preset rate r according to several consecutive pieces of the sampled short message events, determining that the rate of sending short messages by the user is lower than the preset rate r.