Security researchers have discovered that a botnet known as 'Waledec' has successfully cracked nearly 500,000 email accounts, and is likely to start using them to vastly increase its spam activity.
This makes the spam more likely to evade modern filtering techniques, such as IP blacklisting, as the messages will appear to originate from legitimate users.
Source
This makes the spam more likely to evade modern filtering techniques, such as IP blacklisting, as the messages will appear to originate from legitimate users.
Source
