When trying to solve difficult problems, people examine different approaches and strategies. This includes applying known techniques or variations to deliver favorable results. Though variations can be interesting, using a known method has a better chance of getting results. Spammers are no exeption– they are again trying their hand with image spam, seeking an opportunity to catch some anti-spam filters off-guard and sneak through to reach a user’s inbox.
During the last couple of weeks, we have observed an increase in use of images especially with health-related spam. As seen in the past, we also see different obfuscation techniques being used. This includes adding noise to the image to avoid detection of similar images. Along with images, random texts in the message are also observed - again an attempt to bypass the filters. Currently, we don’t see this old technique of using images interfering with anti-spam effectiveness.
We have observed one minor change in the spammers’ approach. Recipients are offered products in multiple currencies during the same spam campaign. As shown below in the images, we see the spammers offering pills in pound sterling as well as U.S. dollars.