- May 29, 2023
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Key Points
- We identified a cluster of at least 16 malicious Chrome extensions used to inject code into browsers to facilitate advertising and search engine optimization fraud. The extensions span diverse functionality including screen capture, ad blocking and emoji keyboards and impact at least 3.2 million users.
- We assess that the threat actor acquired access to at least some of the extensions from their original developers, rather than through a compromise. The threat actor has been trojanizing extensions since at least July 2024.
- The threat actor uses a complex multistage attack to degrade the security of users’ browsers and then inject content, traversing browser security boundaries and hiding malicious code outside of extensions. We have only been able to partly reproduce the threat actor’s attack chain.
- The threat actor may also be associated with phishing kit development or distribution. The malicious extensions present a risk of sensitive information leakage or initial access.