In which of the following malware distribution techniques does the attacker use tactics such as...

The technique described—keyword stuffing, doorway pages, page swapping, and inserting unrelated high-traffic keywords—matchesblack-hat search-engine optimization (SEO), often calledSEO poisoningin digital forensics and threat intelligence materials. In this distribution method, attackers manipulate search engine ranking algorithms so that malicious or malware-hosting pages appear near the top of search results for popular queries (breaking news, software downloads, trending events, adult content, etc.). Doorway pages are created to rank well for specific terms and then funnel victims to malicious landing pages. Page swapping (or “bait-and-switch”) occurs when a page is optimized and indexed as benign content, but later replaced or dynamically served as malicious content once it has gained ranking and trust signals. Keyword stuffing and unrelated keyword injection further exploit ranking heuristics by artificially increasing perceived relevance.

From a forensic perspective, black-hat SEO campaigns often leave artifacts such as compromised websites with injected spam links, abnormal redirect chains, cloaking behavior (different content for crawlers vs. users), and malicious scripts or exploit kit references. The other options do not primarily rely on search ranking manipulation: drive-by downloads are about silent exploitation on visit, spearphishing relies on targeted messaging, and clickjacking tricks users into unintended clicks. Hence,Black-hat search-engine optimization (C)is correct.