Strongly pejorative — official military and police language for an incursion treated as illegitimate (bandits, separatists, smugglers). For a regular military invasion, 入侵 (rùqīn) is the neutral term.
memory
窜 'flee/sneak about' + 犯 'transgress' — sneaking-and-trespassing, the framing always portrays the intruders as cornered and lawless.