Cisco has recommended that people take up ad-blocking tools to defend themselves against the pervasive trend of malicious advertising online.

Analysts at the threat research group Talos argued that script-blockers such as Adblock, Ghostery and RequestPolicy were useful tools against malvertising, which often exploits weaknesses in legitimate networks to attack unsuspecting victims.

Several researchers from Talos wrote on the company blog: "As long as advertising content on popular websites is still being loaded from a multitude of third-parties, malvertising will continue to be a problem for end-users.

"Since most of the time third-party content is seamlessly loaded and integrated inside the browser window, users may be unaware of just how many third parties they are trusting with their security."

Talos found that the infrastructure used in advertising networks was well suited to the demands of scammers, having been "designed specifically to focus Internet traffic towards advertising endpoints", without regards to the validity of the destination.

Hackers are also squatting on domains based on misspellings of legitimate websites, a tactic known as "typosquat" by the researchers, and there is even evidence a piece of software has been developed just to register such domains.

"To help stay under the radar for the past 14 years, the malvertising redirection infrastructure has typically been hosted using IP addresses at shared hosting providers such as Amazon EC2," the Talos researchers said.

"Because many legitimate websites are also hosted at Amazon, hiding among the innocents provides the domains with a bit of additional ‘cover’. This is a common tactic."

Whilst website visitors can protect themselves through script-blockers, companies can also defend their brand and customers by pursuing typosquats through the Uniform Domain-Name Dispute Resolution Policy.