9. A system comprising a hardware computer processor configured to execute a set of instructions to form: a word content phishing filter configured to compute a word content phishing indicator for a target webpage, wherein computing the word content phishing indicator for the target webpage comprises determining a relationship between an index of a word within a target sequence of target word indexes and an index of the word within a reference sequence of reference word indexes, wherein the target word indexes are ordered in the target sequence according to a display order of visible words in the target webpage, and wherein the reference word indexes are ordered in the reference sequence according to a display order of visible words in a reference webpage, wherein the word content fishing indicator for the target webpage is computed according to a quantity selected from a group consisting of a first inter-page word distance and a second inter-page word distance, wherein the first inter-page distance is computed as a function of |Δ 1 |/|A∪B|, wherein the second inter-page word distance is computed as a function of |Δ 2 |/|A∪B|, wherein Δ 1 ={w∈A∩B, so that α−ε≦x w /y w ≦α+ε}, wherein Δ 2 ={w∈A∩B, so that α−ε≦x w −y w ≦α+ε}, wherein w represents a word w, A represents a target wordset of the target webpage, B represents a reference wordset of the reference webpage, ∩ and ∪ represent set intersection and union, respectively, |.| denotes number of elements, x w represents an index of the word w within the target wordset, y w represents an index of the word w within the reference wordset, and wherein α and ε are non-zero parameters; and a phishing risk manager configured to determine whether the target webpage is a phishing page according to the word content phishing indicator.
10. The system of claim 9 , wherein computing the word content phishing indicator comprises identifying a user authentication word sequence formed by all visible words in a user authentication section of the target webpage, wherein the target sequence of target word indexes comprises a target sequence of user authentication word indexes ordered according to a display order of visible words in the user authentication section of the target webpage.