Opening the Image_DIG[random number].htm file with Internet Explorer will lead you to a
website sporting the "Please wait a moment. You will be forwarded…" message intended for making users wait long enough to be surreptitiously redirected to a Russian website hosting the BlackHole exploit kit.
The kit will attempt to take advantage of vulnerabilities present in some of your software, and if it succeeds, you'll end up with malware on your computer.
According to Sophos, more and more of intercepted attacks involve the Blackhole exploit kit, so keeping your computer's anti-virus software and software patches up-to-date as well as learning to exercise caution about opening unsolicited attachments or clicking on unknown links is etremely important.