Hi. I assume you've found the story. It's Ensnared by the Enemy by Alison M. Can't say I thought of it as a poor Mulder story since I never think of Mulder in those terms. I just adore the guy, particularly with Krycek.

It's part of a series. Friends and Enemies, I've just posted part three.
Loved Extreme Measures by Sagitarius, that's well worth a read.