Overview
- CBO said it contained a security incident, deployed additional monitoring and controls, and continues its work for Congress while the probe proceeds.
- Reporting indicates attackers may have accessed internal emails and chat logs, including exchanges between CBO analysts and congressional offices, prompting some offices to pause email correspondence.
- An email from the Senate sergeant at arms advised staff to be wary of links from CBO accounts, and Reuters reporting relayed warnings that compromised emails could be used for phishing.
- Attribution has not been officially confirmed, though a U.S. official told CNN that Chinese state-backed hackers are suspected, and a researcher’s claim about an outdated Cisco firewall as a possible entry point remains unverified.
- The breach is part of a broader wave of federal cyber incidents this year, with response resources constrained by the ongoing government shutdown and recent CISA emergency directives highlighting exploitation of widely used network gear.