Depending on the actual chronology, you might be able to use an old version of f-prot to remove the PKLite container.

The first versions of f-prot's heuristic virus removal software considered PKLite's method of jumping around to replace the PKLite code with the original code entry point to be a viral behaviour, and happily decompressed the binary and stripped off the PK container straight off. Sometimes it left crud on the end, but that didn't harm anything.

Needless to say, both FRISK and PK updated their code to not trample or trigger each other.