For references, here's an example of a website that was simultaneously blocked on a bunch of providers because it matched domain name patterns of a Russia propaganda site: https://www.reddit.com/r/technology/duplicates/38pmg8/hey_re...
Here's a FOIA document from the Center for Strategic Counterterrorism Communications in general about their (mostly overt capabilities to engage the Middle East). They mention DoD covert hacking/DoS capabilities: https://www.muckrock.com/foi/united-states-of-america-10/cen...
There's plenty of this stuff to go around. My favorite (using MRIs to help develop propaganda for Twitter in the Middle East): http://minerva.dtic.mil/doc/samplewp-Lieberman.pdf