ZeuS seems to be a popular and quite successful Trojan at the moment, at least in the UK.
It has been around for a while and has been updated several times (at least 3).
There is an excellent white paper written by M86 Security describing its use in what looks like an ongoing and sustain attack against British Banks.
The latest arrests were announced today where hackers had managed to steal about 20m pounds!
If you search the Internet you can see a trend where British bank customers have been successfully defrauded from their money over the last year, all by hackers using the ZeuS Trojan and for what seems an increasing amount of money!

What I find interesting is the fact money is being stolen at large and increasing scale. Actual money, it is not just an attack which steals information or infects you with 1,000 of pop ups, it is not just targeting large organisation, it is targetting "normal" citizen and their hard earned cash.
Sure it has happened in the past, but what those streams of attacks highlight is the apparent stream lining of (very) profitable attacks which goes on the increase. The technology to mount those attacks is there, the business model supporting and providing that technology is there, and the potential victims are there on the increase.

I have attended several conferences in the past few years where speakers were warning hackers were becoming more organised, professional and focused.
I think we are starting to see the practical effect of that.

Now, if you couple that with the recent LinkedIn spam attack which also attempts to install ZeuS on the victim's computer, then you may have to brace yourself for another wave of infection of potentially wealthy professionals.