Electron is a cross-platform development system for many popular communications apps, including Skype, Slack, and WhatsApp. Security vulnerabilities in the update system allows someone to silently inject malicious code into applications. From a news article:
While making these changes required administrator access on Linux and MacOS, it only requires local access on Windows. Those modifications can create new event-based “features” that can access the file system, activate a Web cam, and exfiltrate information from systems using the functionality of trusted applications — including user credentials and sensitive data. In his demonstration, Tsakalidis showed a backdoored version of Microsoft Visual Studio Code that sent the contents of every code tab opened to a remote website.
Basically, the Electron ASAR files aren’t signed or encrypted, so modifying them is easy.
Note that this attack requires local access to the computer, which means that an attacker that could do this could do much more damaging things as well. But once an app has been modified, it can be distributed to other users. It’s not a big deal attack, but it’s a vulnerability that should be closed.
*** This is a Security Bloggers Network syndicated blog from Schneier on Security authored by Bruce Schneier. Read the original post at: https://www.schneier.com/blog/archives/2019/08/supply-chain_at.html