When Google made its big announcement about an attack originating from China, the company also mentioned that "at least twenty other large companies" had been affected. Now, it's become almost certain that one of them was Adobe, and there are signs that Yahoo was another target.
Adobe's status as a victim became more or less official when a post appeared on a corporate blog. The post stated, "Adobe became aware on January 2, 2010 of a computer security incident involving a sophisticated, coordinated attack against corporate network systems managed by Adobe and other companies."
There was no mention of Google or China, but it's not hard to connect the dots.
As for Yahoo's involvement, an anonymous source told Brian Womack and Ari Levy that it had been hit. Or in so many words: "Yahoo! Inc., owner of the No. 2 search engine in the U.S., was targeted by a Chinese attack similar to the one that affected Google Inc., according to a person familiar with the matter."
There were reports that Facebook, Google, and Twitter teamed up to hunt some hackers following a series of attacks in August of last year. Perhaps, as different companies are connected to the more recent strikes, we'll see another coalition form.