Lawmakers in both houses of Congress are demanding answers from the U.S. Cybersecurity & Infrastructure Security Agency (CISA) after KrebsOnSecurity reported this week that a CISA contractor intentionally published AWS GovCloud keys and a vast trove of other agency secrets on a public GitHub account. The inquiry comes as CISA is still struggling to contain the breach and invalidate the leaked credentials.

On May 18, KrebsOnSecurity reported that a CISA contractor with administrative access to the agency’s code development platform had created a public GitHub profile called “Private-CISA” that included plaintext credentials to dozens of internal CISA systems. Experts who reviewed the exposed secrets said the commit logs for the code repository showed the CISA contractor disabled GitHub’s built-in protection against publishing sensitive credentials in public repos.

CISA acknowledged the leak but has not responded to questions about the duration of the data exposure. However, experts who reviewed the now-defunct Private-CISA archive said it was originally created in November 2025, and that it exhibits a pattern consistent with an individual operator using the repository as a working scratchpad or synchronization mechanism rather than a curated project repository.

In a written statement, CISA said “there is no indication that any sensitive data was compromised as a result of the incident.” But in a May 19 a letter (PDF) to CISA’s Acting Director Nick Andersen, Sen. Maggie Hassan (D-NH) said the credential leak raises serious questions about how such a security lapse could occur at the very agency charged with helping to prevent cyber breaches.

“This reporting raises serious concerns regarding CISA’s internal policies and procedures at a time of significant cybersecurity threats against U.S. critical infrastructure,” Sen. Hassan wrote.

A May 19 letter from Sen. Margaret Hassan (D-NH) to the acting director of CISA demanded answers to a dozen questions about the breach.

Sen. Hassan noted that the incident occurred against the backdrop of major disruptions internally at CISA, which lost more than a third of it workforce and almost all of its senior leaders after the Trump administration forced a series of early retirements, buyouts, and resignations across the agency’s various divisions.

Rep. Bennie Thompson (D-MS), the ranking member on the House Homeland Security Committee, echoed the senator’s concerns.

“We are concerned that this incident reflects a diminished security culture and/or an inability for CISA to adequately manage its contract support,” Thompson wrote in a May 19 letter to the acting CISA chief that was co-signed by Rep. Delia Ramirez (D-Ill), the ranking member of the panel’s Subcommittee on Cybersecurity and Infrastructure Protection. “It’s no secret that our adversaries — like China, Russia, and Iran — seek to gain access to and persistence on federal networks. The files contained in the ‘Private-CISA’ repository provided the information, access, and roadmap to do just that.”

KrebsOnSecurity has learned that more a week after CISA was first notified of the data leak by the security firm GitGuardian, the agency is still working to invalidate and replace many of the exposed keys and secrets.

On May 20, KrebsOnSecurity heard from Dylan Ayrey, the creator of TruffleHog, an open-source tool for discovering private keys and other secrets buried in code hosted at GitHub and other public platforms. Ayrey said CISA still hadn’t invalidated an RSA private key exposed in the Private-CISA repo that granted access to a GitHub app which is owned by the CISA enterprise account and installed on the CISA-IT GitHub organization with full access to all code repositories.

“An attacker with this key can read source code from every repository in the CISA-IT organization, including private repos, register rogue self-hosted runners to hijack CI/CD pipelines and access repository secrets, and modify repository admin settings including branch protection rules, webhooks, and deploy keys,” Ayrey told KrebsOnSecurity. CI/CD stands for Continuous Integration and Continuous Delivery, and it refers to a set of practices used to automate the building, testing and deployment of software.

KrebsOnSecurity notified CISA about Ayrey’s findings on May 20. Ayrey said CISA appears to have invalidated the exposed RSA private key sometime after that notification. But he noted that CISA still hasn’t rotated leaked credentials tied to other critical security technologies that are deployed across the agency’s technology portfolio (KrebsOnSecurity is not naming those technologies publicly for the time being).

CISA responded with a brief written statement in response to questions about Ayrey’s findings, saying “CISA is actively responding and coordinating with the appropriate parties and vendors to ensure any identified leaked credentials are rotated and rendered invalid and will continue to take appropriate steps to protect the security of our systems.”

Ayrey said his company Truffle Security monitors GitHub and a number of other code platforms for exposed keys, and attempts to alert affected accounts to the sensitive data exposure(s). They can do this easily on GitHub because the platform publishes a live feed which includes a record of all commits and changes to public code repositories. But he said cybercriminal actors also monitor these public feeds, and are often quick to pounce on API or SSH keys that get inadvertently published in code commits.

The Private-CISA GitHub repo exposed dozens of plaintext credentials to important CISA GovCloud resources.

In practical terms, it is likely that cybercrime groups or foreign adversaries also noticed the publication of these CISA secrets, the most egregious of which appears to have happened in late April 2026, Ayrey said.

“We monitor that firehose of data for keys, and we have tools to try to figure out whose they are,” he said. “We have evidence attackers monitor that firehose as well. Anyone monitoring GitHub events could be sitting on this information.”

James Wilson, the enterprise technology editor for the Risky Business security podcast, said organizations using GitHub to manage code projects can set top-down policies that prevent employees from disabling GitHub’s protections against publishing secret keys and credentials. But Wilson’s co-host Adam Boileau said it’s not clear that any technology could stop employees from opening their own personal GitHub account and using it to store sensitive and proprietary information.

“Ultimately, this is a thing you can’t solve with a technical control,” Boileau said on this week’s podcast. “This is a human problem where you’ve hired a contractor to do this work and they have decided of their own volition to use GitHub to synchronize content from a work machine to a home machine. I don’t know what technical controls you could put in place given that this is being done presumably outside of anything CISA managed or even had visibility on.”

Update, 3:05 p.m. ET: Added statement from CISA. Corrected a date in the story (Truffle Security said it found the repo gained some of its most sensitive secrets in late April 2026, not 2025).

Canadian authorities on Wednesday arrested a 23-year-old Ottawa man on suspicion of building and operating Kimwolf, a fast spreading Internet-of-Things botnet that enslaved millions of devices for use in a series of massive distributed denial-of-service (DDoS) attacks over the past six months. KrebsOnSecurity publicly named the suspect in February 2026 after the accused launched a volley of DDoS, doxing and swatting campaigns against this author and a security researcher. He now faces criminal hacking charges in both Canada and the United States.

A criminal complaint unsealed today in an Alaska district court charges Jacob Butler, a.k.a. “Dort,” of Ottawa, Canada with operating the Kimwolf DDoS botnet. A statement from the Department of Justice says the complaint against Butler was unsealed following the defendant’s arrest in Canada by the Ontario Provincial Police pursuant to a U.S. extradition warrant. Butler is currently in Canadian custody awaiting an initial court hearing scheduled for early next week.

The government said Kimwolf targeted infected devices which were traditionally “firewalled” from the rest of the internet, such as digital photo frames and web cameras. The infected systems were then rented to other cybercriminals, or forced to participate in record-smashing DDoS attacks, as well as assaults that affected Internet address ranges for the Department of Defense. Consequently, the DoD’s Defense Criminal Investigative Service is investigating the case, with assistance from the FBI field office in Anchorage.

“KimWolf was tied to DDoS attacks which were measured at nearly 30 Terabits per second, a record in recorded DDoS attack volume,” the Justice Department statement reads. “These attacks resulted in financial losses which, for some victims, exceeded one million dollars. The KimWolf botnet is alleged to have issued over 25,000 attack commands.”

On March 19, U.S. authorities joined international law enforcement partners in seizing the technical infrastructure for Kimwolf and three other large DDoS botnets — named Aisuru, JackSkid and Mossad — that were all competing for the same pool of vulnerable devices.

On February 28, KrebsOnSecurity identified Butler as the Kimwolf botmaster after digging through his various email addresses, registrations on the cybercrime forums, and posts to public Telegram and Discord servers. However, Dort continued to threaten and harass researchers who helped track down his real-life identity and dramatically slow the spread of his botnet.

Dort claimed responsibility for at least two swatting attacks targeting the founder of Synthient, a security startup that helped to secure a widespread critical security weakness that Kimwolf was using to spread faster and more effectively than any other IoT botnet out there. Synthient was among many technology companies thanked by the Justice Department today, and Synthient’s founder Ben Brundage told KrebsOnSecurity he’s relieved Butler is in custody.

“Hopefully this will end the harassment,” Brundage said.

An excerpt from the criminal complaint against Butler, detailing how he ordered a swatting attack against Ben Brundage, the founder of the security firm Synthient.

The government says investigators connected Butler to the administration of the KimWolf botnet through IP address, online account information, transaction records, and online messaging application records obtained through the issuance of legal process. The criminal complaint against Butler (PDF) shows he did little to separate his real-life and cybercriminal identities (something we demonstrated in our February unmasking of Dort).

In April, the Justice Department joined authorities across Europe in seizing domain names tied to nearly four-dozen DDoS-for-hire services, although because of a bureaucratic mix-up the list of seized domains has remain sealed until today. The DOJ said at least one of those services collaborated with Butler’s Kimwolf botnet.

A statement from the Ontario Provincial Police said a search warrant was executed on March 19 at Butler’s address in Ottawa, where they seized multiple devices. As a result of that investigation, Butler was arrested and charged this week with unauthorized user of computer; possession of device to obtain unauthorized use of computer system or to commit mischief; and mischief in relation to computer data. He is scheduled to remain in custody until a hearing on May 26.

In the United States, Butler is facing one count of aiding and abetting computer intrusion. If extradited, tried and convicted in a U.S. court, Butler could face up to 10 years in prison, although that maximum sentence would likely be heavily tempered by considerations in the U.S. Sentencing Guidelines, which make allowances for mitigating factors such as youth, lack of criminal history and level of cooperation with investigators.