The attacks were targeted at these investors, and the code was custom written, according to the story. The infections and the centralized control over the botnet made it possible for the botmaster to time all of the infected systems to buy or sell shares concurrently. This attack is another example of just how sophisticated cyber attacks have become, and how useless traditional anti-virus systems are in combating modern threats.
Many security experts aren't offering viable answers to these problems. In response to the attack, a Trend Micro blog in Europe suggests each banking transaction be verified to stop such attacks:
. . . from conversations with a local journalist today it seems that many Belgian banks (in fact most banks globally) are still only offering classical two-factor authentication aimed at authenticating the user rather than the transaction. While this kind of technology would certainly thwart this bot in its current form it is not impossible to defeat. As I have previously blogged banking malware has already evolved to the stage where it can overcome multiple factor user authentication.
With this in mind it is vital that any improvment (sic) in online banking security should verify individual transactions rather than simply authenticate the user. The authentication token itself must be capable of accepting direct input relating to the content or the value of the transaction. This can then be verified by both parties and cannot be modified by the malicious "man in the browser".
I'm not sure what the majority of banks in Europe are doing to authenticate users. Most online financial systems here in the U.S. still rely on single factor authentication (username/password). I am quite sure, however, most stock traders wouldn't want their trades to be vetted by some algorithm or other form of approval. It's yet another hoop to jump and additional friction between the trader and the execution of the trade.
In addition, the security mistakes made here don't appear to be the fault of the banks, rather the fault of the stock traders themselves: somehow their systems got infected with these bots and were then permitted to execute the rogue trades.
The insidious fact is, as technology stands today, these types of attacks can affect anyone. All it takes is visiting an infected blog or news Web site and it is possible for attackers to inject the malware on end user systems. It's not yet been made public how the stock traders became infected - but infected web sites frequented by traders, or highly targeted phishing e-mails with the attack software attached are reasonable assumptions.
What's the average user to do? My advice is to establish a dedicated system for banking - and don't visit any other web sites or do any other functions on that system. Period. One could also create highly secure virtual machines dedicated to banking and financial services, and revert back to a trusted safe image every day.
Not a convenient answer: but until we get control over the security of the Web and web browsers it just may be the most secure.
For my security and business observations throughout the day, consider following me on Twitter.