The number of people affected by the data breach at Monster.com is now estimated an 1.6 million. This is up from initial reports of only 46 thousand. This breach was part of an elaborate plan to steal information on hold computers hostage for ransom.

The plan started with installing a trojan horse on users computers who used Monster.com to apply for jobs. The trojan horse was installed through ads on the site. The second step was to send credible phishing emails in an effort to install two pieces of malware.

The first piece of malware is an information-stealing Trojan horse that monitors the infected PC for log-ons to online banking accounts. When the malware sniffs a log-on in process, it records the username and password, then transmits the data back to the hacker. The second piece of malware is often called ransomware. This is a trojan horse that encrypts files on the hacked computer, then hold those files hostage until the user pays a fee to unlock the data.