A government could use covert access to the IMF's computers to keep ahead of the steps the Fund and World Bank take to stabilize exchange rates, among other things, Kellerman said.
The memo announcing the breach to staff said many files were compromised, but that the IMF didn't believe any of the information taken was of the kind of sensitive or personal nature that would make identity theft likely.
Some experts are still wasting words blaming Anonymous for every hack and data breach from the IMF to the loss of the email address of that attractive sales rep they met at a conference in Vegas last month.
Odds are we won't ever know for sure who attacked the IMF, just as we don't know who launched Stuxnet against Iran.
The most likely culprit is the one that is the source of the highest number of high-profile breaches of government or financial-services data.
Ten years ago that might have been organized-crime groups in Eastern Europe, though they tended more toward online extortion and outright theft.
The current leader is China, which goes after exactly the kind of information a keylogger or data-acquisition program would get by sitting quietly inside a compromised desktop and listening as the IMF goes about its regular business.
Other countries – most of the Third World, which is much more heavily dependent on the IMF and World Bank than the First World, would be interested, but might have fewer all-but-provable attacks on the record against Western targets.
Russia and other former eastern-bloc countries are also possible candidates, though less likely than Iran, China or one of the other powerful, wealthy, technologically savvy nations elbowing each other for a better spot in the international hierarchy.
That approach would be too unlikely to turn up data that could turn an immediate profit to satisfy plain old mafiosi.
It's way too quiet and non-confrontational for groups like Anonymous, which protest by bringing down public sites with as much noise and fury as possible.
Besides, the IMF was ready for them.