As defenders get better at spotting traditional vectors like email phishing and trojanized software, threat actors are shifting focus to less obvious channels—one of the most concerning being malvertising: the injection of malicious code into legitimate advertising networks.

How It Works

Malvertising doesn't require a user to download anything directly. Instead, attackers buy ad space through compromised or poorly vetted ad networks and serve JavaScript-based exploits that run the moment a user visits a page. These exploits often target browser vulnerabilities, out-of-date plugins, or misconfigured settings to silently deploy payloads.

Even well-known sites aren’t immune. In early 2025, researchers observed malicious ads running through third-party ad slots on high-traffic entertainment and gaming platforms, including streaming sites, freemium gaming portals, and even real-money gambling directories.

Exploiting Trust and Entertainment

One reason this tactic is so effective is because users lower their guard when visiting casual, entertainment-based platforms. Attackers know this. They often clone or inject into pages mimicking real money online casino review sites, which attract huge traffic from mobile users—a demographic less likely to have hardened security settings.

Interestingly, some researchers use legitimate casino comparison platforms like CasinoGamesForRealMoney.com as benchmarks to analyze what clean, secure site behavior looks like. By comparing resource loads, domain histories, and iframe behavior from verified sources, it's easier to identify malicious redirections and rogue scripts.

Payloads & Redirection Chains

Once a user clicks (or even just views) a malicious ad, they might be redirected through a chain of exploit kit servers. Common payloads include:

• Info-stealers targeting saved browser passwords

• RATs for remote access

• Drive-by crypto miners

• Fake software updates prompting additional downloads

In some cases, attackers use geolocation-based payloads, only activating the malicious script if the IP matches a certain region—making detection harder for global threat intel teams.

Mitigation & Research

For penetration testers and threat analysts, investigating these malvertising chains can offer valuable insight. Tools like:

• Browser traffic capture (Fiddler/Burp Suite)

• JS sandbox environments

• Ad network domain mapping

…can all help trace and replicate the attack chain.

Final Thoughts

Malvertising is effective precisely because it blends into normal user behavior. Understanding where attackers place their traps—including fake gambling reviews or mobile-optimized platforms—can improve both red team tactics and defensive heuristics.