Image spam makes a come back
Spammers have resumed sending image spam in a new attempt to mislead spam filters. The current stream of spam messages using images is comparable with the messages that were sent by spammers a few years ago.
Most cases contain advertizements for drugs and use the same images. Besides the regular spam filter poison, some spammers also add random pixels to the image to try to avoid detection by spam filters.
Caretaker Antispam is not sensitive to this spam filter poison and random pixels, and uses since its introduction techniques to detect image spam. It can read easily the text in the image because it separates information on the foreground from the background:
- 10.0 OCR: inline image contains the word 'viagra'
- 10.0 OCR: inline image contains the word 'ultram'
- 10.0 OCR: inline image contains the word 'levitra'
- 3.5 OCR: inline image has text (97.1%)
Instead of sending formatted or unformatted text, spammers hide their message in an image as they did in 2006 and 2007. Image spam increased recently to about 10% of the total amount of spam messages.
Click here for more information about Caretaker Antispam and image spam.