Recently, malware vendors have been purchasing popular Chrome extensions in order to distribute malicious code, adware and malware to every user of the extension.
According to ArsTechnica, the danger lies in Chrome's 'silent updates': Google designed Chrome specifically to be smooth and noninvasive, which means silently updating browsers and extensions without a hitch. But it also means that users aren't told when ownership of an extension is transferred to another company - so they're left in the dark if a malicious vendor suddenly decides to push dangerous updates.
And as it turns out, exactly that has been happening. Adware vendors are purchasing popular extensions and subsequently pushing out silent updates filled with malicious and invasive code to users' browsers. This was experienced firsthand by the developer of the popular 'Add to Feedly' extension: A mysterious buyer approached him and offered him a four-figure sum to transfer ownership of the extension that he had developed. When he took them up on their offer, the new owners pushed out an update which pumped the extension full of adware, leaving the extension's 30,000 users at the short end of the stick with potentially compromised browsers.
The internet certainly isn't a novice to this sort of malware. A few weeks ago, Yahoo confirmed that some of the ads on its site were filled with malicious code - and even Google is aware of the issue, implementing 'malware detection' into a beta browser back in November. But as the Chrome web browser becomes more and more popular, the prevalence of folks looking to harm your computer and steal your personal information will certainly increase in turn.