So why would the malware not just check the C&C server for orders? Why hope that your victim checks Twitter and sees your memes? This seems like a really roundabout way of accomplishing something trivial (I mean, trivial as compared to infecting a machine with your malware in the first place...)

If your C&C server has been "compromised" or blocked by, say, law enforcement, the tweets could instruct malware to use another?

Perhaps the malware will sit idle like a "sleeper" agent until activated, and you want to reduce the chance of preemptive detection.

Having its background polling look like a typical Twitter user agent would help it remain hidden and ensure that its command channel is not blocked. (At least for a large class of victims who do not have severe network restrictions in effect.)

You could also send the destination address via Twitter, so that the malware does not leak information about the controller ahead of its activation or so that the controller can make last minute arrangements of temporary resources...

Because that would reveal the location (IP address) of the C&C server, in addition to making it a point of failure.

But the output of all the commands still sends to the C&C server, so I don't see how this protects that. Unless, as the other user suggested, the memes could actually also contain the IP to use for the C&C server. So the "order" is akin to "upload username to ###.##.###.#"

you could ex-filtrate data by the same mechanism though (e.g posting images to twitter)

That might attract some attention, for example, in a corporate environment where everything is locked down.

In reality the amount of alerts a SOC has to triage is so big on avg I doubt they would really be looking into someone accessing twitter.

Some things will seem very innocent though. Having a video call with a family member while sending out data under the noise floor.