Malicious Chrome Extensions Steal and Inject Session Cookies to Hijack Enterprise Accounts
Researchers reported a coordinated operation involving at least five malicious Chrome extensions masquerading as productivity or security tools, designed to hijack enterprise web sessions by stealing authentication cookies/session tokens. The extensions targeted business platforms such as Workday, NetSuite, and SAP SuccessFactors, where possession of a valid session token can enable access without re-entering credentials; telemetry indicated some variants attempted to exfiltrate cookies as frequently as every 60 seconds. Prior to takedown requests to Google, the campaign was estimated to have reached 2,300+ installs.
One variant, Software Access, was described as particularly advanced because it supported bidirectional cookie injection—using Chrome APIs such as chrome.cookies.set() to implant stolen session cookies into an attacker-controlled browser, effectively recreating an authenticated session. Investigators noted the extensions shared identical infrastructure patterns despite being published under different names (including multiple under “databycloud1104”), supporting attribution to a single coordinated actor. Recommended mitigations included stricter enterprise controls over browser extensions (vetting and limiting permissions, especially cookie access), removing unnecessary add-ons, and monitoring for anomalous session activity and extension behavior to detect session hijacking attempts earlier.
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How this story unfolded
4 events from the most recent confirmed update back to the earliest known activity.
Researchers link five extensions to one coordinated campaign
Analysis showed that four extensions were published under the name "databycloud1104" and one under a different brand, but all shared the same infrastructure patterns. Researchers concluded the five add-ons were part of a single coordinated operation focused on cookie theft and session hijacking.
Researchers alert Google and seek takedown of the extensions
After identifying the malicious behavior, researchers warned Google's security team and submitted takedown requests for the Chrome Web Store listings. Before that intervention, the extensions were estimated to have been installed by more than 2,300 users.
Extensions steal session cookies and enable account hijacking
Researchers found the extensions exfiltrated authentication cookies to attacker-controlled infrastructure, in some cases every 60 seconds, allowing passwordless access to enterprise systems. The most advanced sample, "Software Access," also supported cookie injection via browser APIs to implant stolen session tokens into an attacker-controlled browser.
Malicious Chrome extensions published to target enterprise HR/ERP sessions
A coordinated set of five Chrome extensions was made available through the Chrome Web Store while masquerading as productivity or security helper tools. The extensions targeted enterprise environments using platforms such as Workday, NetSuite, and SuccessFactors and were presented with polished listings to appear legitimate.
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