1. A computer-implemented method comprising employing at least one computer processor to perform the steps of: generating a target sequence of target word indexes for a set of visible words of a target webpage, wherein the target word indexes are ordered in the target sequence according to a display order of visible words in the target webpage; computing a word content phishing indicator for the target webpage by determining a relationship between an index of a word within the target sequence of target word indexes and an index of the word within a reference sequence of reference word indexes, 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 phishing 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 making a determination whether the target webpage is a phishing page according to the word content phishing indicator.
6. The method of claim 1 , further comprising 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.