One imposing cuts a threat to security? (6)

I believe the answer is:

hacker

(Other definitions for hacker that I've seen before include "Modern thief who breaks into computer systems" , "PM on TV" , "one's riding for pleasure" , "Modern word for unauthorised intruder in computer system" , "One breaks into computer systems for nefarious purposes" .)

I've seen this clue in The Sun.

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