Hackers are increasingly using black hat SEO techniques to manipulate search engine results and boost the visibility of malicious or fraudulent websites. Zscaler cybersecurity researchers have noted a recent surge in fraudulent sites hosted on well-known web hosting services and blogging platforms. These sites are utilized by threat actors for SEO poisoning and malware distribution, exploiting the legitimacy of hosting platforms to quickly elevate the ranking of harmful content in search results. By appearing higher in search results, these sites gain more traffic and deceive more users into downloading malicious software.
These malicious websites operate by creating fake sites that go unnoticed by the hosting services, allowing them to carry out their nefarious activities undetected. Users are directed to these sites through manipulated search results, often bypassing direct URL access which might expose them to security analysis. The sites employ techniques to check the referral URLs; if the traffic comes from search engines, the malicious content is displayed, but if there is direct access, it may not proceed to avoid detection by security researchers.
A key tactic used by these sites involves sophisticated obfuscation methods to conceal their malicious intent. For example, the malicious payload might be hidden in nested, password-protected ZIP archives with the password cleverly hidden within an image to evade detection. Additionally, the malware installer uses techniques like DLL sideloading to drop malicious code alongside legitimate software, complicating detection and analysis.
The final stage of these attacks involves multiple layers of obfuscation, including encoded sections and self-decrypting scripts that are executed to perform malicious actions. These actions include creating shortcuts that load harmful browser add-ons and communicating with command-and-control servers to download further malicious payloads. The malware extension steals a vast amount of data from the infected machines, including system information, browser cookies, credentials, and more, all while disguising its network traffic by querying blockchain.info for the C2 domain via a Bitcoin address.
