First, cybercriminals were using iFrames in websites to try to take over the Domain Name Server (DNS) settings of home routers, but now they’re using malware injected into advertisements online to attack consumers, according to security researchers.

Fioravante Souza, an analyst from Sucuri, published a blog post outlining how malware-based advertising, also known as “malvertising,” was the approach taken by cybercriminals in an attempt to reboot the DNS settings of home routers and flush the cache. Sucuri said its tests didn’t lead to any malicious websites, however, indicating those responsible may be waiting to launch a full-fledged attack.

Cybercriminals appear to be looking at the DNS settings of home routers as an increasingly popular way of compromising the security of personal information. Just last month, experts discovered malicious software was injected into the iFrames of a popular Brazilian newspaper that attempted to guess the default passwords of home routers by running an automated script.

According to HelpNet Security, this latest attack on home routers was distributed through Googlesyndication.com, an online ad network that serves up ads across a wide range of websites. This marks the second time in just a few weeks that Google has fallen victim to malvertising. In September, both Google-owned Doubleclick and Zedo, another popular ad network, were hit with Zemot, a malware bundle that connects to remote servers to perpetrate an attack as widely as possible.

As SensorsTechForum.com noted, the researchers at Sucuri had to comb through nearly 3,000 blank characters in order to identify the malicious code aimed at the DNS settings of home routers. In other words, cybercriminals are going to ever-greater lengths to make such attacks difficult to detect.

The Googlesyndication.com domain is associated with Google Adsense, one of the most common platforms used by marketers to manage online ad campaigns, according to ThreatBrief. If cybercriminals manage to take over the DNS settings of a home router, it could redirect to a different IP address in order to serve up malware-infected content.

Though Softpedia and others reported the attack was likely run out of Los Angeles, no other details around the attackers have surfaced so far. As always, this is a good time for consumers to make sure they have secure, up-to-date passwords — and that they think twice about clicking on an online ad they’re unsure about.