A method for preventing session initiation protocol (SIP) attacks is provided. The method includes receiving a plurality of SIP response messages comprising at least one pre-defined SIP response code, and extracting at least one user identifier from the plurality of SIP response messages. The method further includes computing at least one of a frequency of the plurality of SIP response messages and a count of the plurality of SIP response messages corresponding to each user identifier of the at least one user identifier. The method further includes calculating a degree of attack corresponding to each user identifier using at least one of the frequency and the count. The method further includes determining a monitoring interval for each user identifier based upon the degree of attack for monitoring the plurality of SIP response messages. An apparatus and a computer program product for preventing SIP attacks are also provided.