According to the most recent reports of the IT security companies Sophos and Symantec the figure of graphic spam is about 30-40% in the total sum of spam mail. The most awful thing about it is that often such emails direct to clutch through the filters, no issue how powerful is the installed anti-spam product. By graphic spam experts indicates two types of emails: mails enclosing only an image or those containing both a image and a few text. The major crisis for spam filters is advertisement mails enclosing only graphic files. These types of spam are acquiring more and more popular and turn into a factual tackle for the companies producing anti-spam software.
The initiative of graphic spam was introduced a long time ago but fairly soon after that spam-filters became skilled of identifying such messages. However spammers have initiated new techniques to create advertisement images that are extremely tricky to detect using known approaches. The approaches presently exercised for detecting graphic spam are based on comparing attached files with so-called graphic signatures. In sort to hoax these technologies particular programs are altering initial files and make numerous trivially different images by altering colors, changing borders, tilting several letters or restoring the background. So, when spam messages are sent there are no similar images in them, which create spam detection considerably more difficult.
Spammers are using multilayer images when letters and words are hacked into elements, which are distributed between different frames, and only viewing the entire animated image a reader can notice the whole text of the advertisement.
One of the comparatively new types of graphic spam is PDF-documents. Symantec experts have previously spotted numerous varieties of this type. In one case a PDF-file was just a news message and the letter was created professionally so it didn’t look doubtful at all. In another case, a similar letter was sent with an attached PDF-document that showed to be graphic spam in the trust that the letter will not be detected by spam filters.
Actually, spammers think graphic type of spam as a hopeful technology, which unties many methods to avoid detection by anti-spam software, and will broadly grow it. This implies that in the nearby prospect the amount of “spam in images” will be developing quickly. However, the latest versions of anti-spam software are prepared to meet the dispute and are already skilled of detecting many types of graphic spam.