As it pursues a libel complaint against DoubleVerify, FilmOn Networks has told Scotland Yard and the FBI that the online advertising verification company is deliberately distributing malware.

DoubleVerify has drawn the ire of the Web video streaming company by claiming flagging it—inappropriately, FilmOn says—as a porn site and accusing it of copyright infringement. While FilmOn at one point did live stream local TV broadcasts, it ceased the practice following a string of lawsuits.

When FilmOn began compiling information for its suit, filed Monday in Superior Court in Los Angeles, according to a story on its website, it also uncovered malware that reportedly is linked to a pop up ad scheme that has done damage around the globe. FilmOn fingered DoubleVerify as in control of the virus.  

The companies' CEOs traded barbs and accusations in a Wednesday Wall Street Journal blog post.