Rush him!

You sprint forward as the door opens, slamming a claw into his chest. He topples backwards, screaming in pain, and you tear his throat out with another claw to shut him up. His comrades look up from their searching, see you, and curse as they go for their guns. You roar, drop his corpse, and charge towards the next soldier...

BLAMBLAMBLAMBLAMBLAM.

Most of the shots either bounce off your carapace or miss, but two get through. One splatters your brain against a cargo container and the other one drills through your top right hand (not that it matters.)

With the soldiers alerted to 'stealer presence, they close in on the container, pumping rounds into it as they move. Your broodbrothers might be fast, but they can't dodge shots they don't know are coming, can't dodge in such a tight space, and can't dodge such a mass of fire.

They die, your cultist dies, and the Hive Fleet, for want of a food source that won't blow their home from the sky and kill their only Norn Queen as soon as they try to eat, dies.

Later, when the full truth is known to the Imperium, it's repackaged as propaganda, talking about how dumb xenos are, and about how a few heroic PDF members saved their world from a horrible fate.