This is off-topic, but I am reminded of the sci-fi novel Eternity by Greg Bear, in which the protagonist Olmy downloads a copy of an alien Jart mind into his nanowear to study it. Turns out this was a trojan horse, and the Jart escapes the confines of the sandbox.

The "Blight" in "A Fire Upon the Deep"[0] comes to mind for me.

[0] https://en.wikipedia.org/wiki/A_Fire_Upon_the_Deep