Pressure is mounting on Instructure, the company behind Canvas, as cybercriminals threaten to leak a trove of sensitive data they claim was stolen during a prolonged cyberattack on the widely used education tech platform.

Widespread outages left schools, students and teachers temporarily unable to access critical data late last week after the company took Canvas offline following additional malicious activity, including a defacement of the platform’s login page. By Friday, the company said Canvas — a central hub for K-12 and university coursework, exams, grades and communication — was back online and fully operational. 

ShinyHunters, a decentralized crew of prolific cybercriminals affiliated with The Com, claimed responsibility for the attack on its data leak site and is attempting to extort the company for an unknown ransom amount. Instructure hasn’t confirmed the existence of a ransom demand and declined to answer questions about its response.

The threat group initially set a deadline of May 6 — four days after Instructure previously said the incident was contained soon after it disclosed the attack — claiming it stole 3.65 terabytes of data spanning 275 million records across 8,809 school systems. 

When that deadline passed without payment, ShinyHunters escalated its pressure on the company by “injecting an extortion message directly into the Canvas login pages of roughly 330 institutions, and pivoted to school-by-school extortion with a current deadline of May 12,” Cynthia Kaiser, senior vice president of Halcyon’s Ransomware Research Center, told CyberScoop.

“The scope makes this one of the largest single education-sector exposures we’ve tracked,” she added.

The additional public pressure prompted Infrastructure to take Canvas offline, disrupting schoolwork and access to critical systems nationwide. 

Instructure CEO Steve Daly apologized over the weekend for the company’s inconsistent communication and deficient public response to the cyberattack. 

“Over the past few days, many of you dealt with real disruption. Stress on your teams. Missed moments in the classroom. Questions you couldn’t get answered. You deserved more consistent communication from us, and we didn’t deliver it. I’m sorry for that,” he said in a statement.

Daly acknowledged that the attack, which remains under investigation aided by CrowdStrike, exposed usernames, email addresses, course names, enrollment information and messages. He insisted that course content, submissions and credentials were not compromised.

The temporary but widespread disruption caused has spurred broad concern across the education sector as ransomware experts and threat hunters continue to track developments. The cyberattack also caught the attention of lawmakers on Capitol Hill. 

The House Homeland Security Committee on Monday published a letter to Daly seeking a briefing with him or a senior leader at Instructure by May 21. 

“The recurrence of an intrusion within days of an initial breach disclosure, and Instructure’s apparent failure to fully remediate the underlying vulnerabilities during that window, raise serious questions about the company’s incident response capabilities and its obligations to the institutions and individuals whose data it holds,” House Homeland Security Chairman Andrew Garbarino, R-N.Y., wrote in the letter to Daly.

The committee wants to learn more about the “circumstances of both intrusions, the the nature and volume of data accessed, the steps Instructure has taken and is taking to contain the threat and notify affected institutions, and the adequacy of the company’s coordination with federal law enforcement and the Cybersecurity and Infrastructure Security Agency,” he added. 

CISA did not describe the extent of its involvement in Instructure’s response. “CISA is aware of a potential cyber incident affecting Canvas. As the nation’s cyber defense agency, we provide voluntary support and cybersecurity services to organizations in responding to and recovering from incidents,” Chris Butera, the agency’s acting executive assistant director for cybersecurity, said in a statement.

Instructure’s timeline of the attack has changed and remains incomplete. The company said it first detected unauthorized activity in Canvas on April 29 and immediately revoked the attacker’s access and initiated an incident response. Researchers not directly involved with the formal investigation said ShinyHunters gained access to Canvas at least a few days earlier.

The follow-on malicious activity on May 7 — the defacement of public login pages — was tied to the same incident, the company said. 

“We have since confirmed that the unauthorized actor carried out this activity by exploiting an issue related to our Free-For-Teacher accounts. This is the same issue that led to the unauthorized access the prior week. As a result, we have made the difficult decision to temporarily shut down Free-For-Teacher accounts,” the company said in an updated post about the incident.

Instructure did not answer questions about the vulnerability or explain how attackers intruded its systems. The company said it also revoked privileged credentials and access tokens for affected systems, rotated internal keys, restricted token creation pathways, and deployed additional security controls and monitoring.

Canvas is fully operational and safe to use, the company said, adding that CrowdStrike has reviewed known indicators of compromise and “found no evidence that the threat actor currently has access to the platform.”

Access still remains spotty and unavailable for some Canvas users as school districts restore the platform in phases after conducting their own internal checks.

Halcyon published an alert about the attack Friday, including a screenshot of the message that some school staff, guardians and students encountered before Instructure took the learning management system offline.

ShinyHunters threatened Instructure and all affected schools to contact the threat group and reach a resolution by end of day Tuesday. The cybercrime group, which has a “known pattern of removing victim entries once communications and negotiations have started,” removed Instructure from its data leak site after it defaced the Canvas login pages, Halcyon said. 

ShinyHunters is a notorious data theft extortion group that previously hit major cloud platforms, including Salesforce and Snowflake, via voice phishing, credential theft and supply-chain attacks. 

“Historically, their claims of compromise typically hold up, but they often exaggerate the impact, scale, and type of data stolen,” Kaiser said.

Education is a recurring and consistent target for cybercriminals. Researchers at Halcyon tracked more than 250 ransomware attacks on education institutions globally last year. Yet, the attack on Canvas stands apart from most of these attacks because of its widespread use and downstream impact.

“This is student, parent, and staff data, including minors, which creates downstream phishing and impersonation risk that will outlast the immediate incident,” Kaiser said. 

“By compromising a shared platform used across thousands of schools, ShinyHunters hit the entire education sector in one move, which is the same playbook Clop ran against Oracle EBS customers last fall,” she added. “Among 2026 incidents against critical infrastructure, this is at or near the top for education-sector impact, and it highlights a trend of third-party software vendors now being part of an attack surface, and causing cascading effects across an entire sector.”

Cybersecurity professionals focused on ransomware and data theft extortion consistently encourage victims to not pay ransoms, but they also often acknowledge that companies have to make tough decisions based on their own interests and the security of their customers or users caught up in the aftermath.

Allison Nixon, chief research officer at Unit 221B, said the threat group claiming responsibility for the attack should not be trusted. 

“They are claiming they will delete the data after they are paid, and if they are not paid that they will leak the data,” she told CyberScoop. “This is in line with the past data extortion scams run by the same and related Com actors, who have made false statements to victims and to the public in the past.”

Instructure hasn’t indicated what it plans to do as part of any effort to prevent the leak of stolen data. 

Daly — a longtime security executive who was previously CEO at Ivanti — ended his mea culpa with a pledge to improve communications and provide a summary of a forensics report soon.

“Last week, we made a call to get the facts right before speaking publicly. That instinct isn’t wrong, but we got the balance wrong. We focused on fact-finding and went quiet when you needed consistent updates. You’ve been clear about that, and it’s fair feedback. We will change that moving forward,” he said. 

“Rebuilding trust takes time,” Daly added. “We’re going to earn it back through consistent action and honest communication.”