A massive cyberattack that led to avulnerability in RSA's SecurID tags earlier this year also victimized Google, Facebook, Microsoft and many other big-named companies, according to a new analysis released this week.

A list of 760 organizations that were attacked using the same resources deployed to hack RSA was presented to Congress recently and published by security analyst Brian Krebs on his blog Monday.

he names mentioned on Krebs' list include about a fifth of the Fortune 100, as well as many other massive corporations. Abbot Laboratories (ABT, Fortune 500), Charles Schwab (SCHW, Fortune 500), Freddie Mac, PriceWaterhouseCoopers and Wells Fargo (WFC,Fortune 500) are all named. Tech giants like Amazon (AMZN, Fortune 500), IBM (IBM, Fortune 500), Intel (INTC, Fortune 500), Yahoo (YHOO, Fortune 500), Cisco (CSCO, Fortune 500), Google (GOOG, Fortune 500), Facebook, and Microsoft (MSFT, Fortune 500) are also included, as well as government agencies like the European Space Agency, the IRS, and the General Services Administration. Government security contractor Northrop Grumman (NOC, Fortune 500) was on the list, as was MIT.

But there's a big caveat: As Krebs was quick to note, many Internet service providers were on the list, most likely because their subscribers were attacked using their network, not because the companies themselves were compromised. That means that companies like Comcast (CMCSA,Fortune 500), Windstream (WIN), Verizon (VZ, Fortune 500), AT&T (T, Fortune 500) and Sprint (S, Fortune 500) may be off the hook.