APT28 Reuses Old Access and Roundcube Exploits Against Ukrainian Institutions
Ukrainian officials warned that Russia-linked hackers are revisiting earlier compromises to regain access to government and defense networks, testing whether old footholds, unpatched vulnerabilities, and previously stolen credentials still work. CERT-UA said the activity reflects a broader shift from smash-and-grab credential theft toward persistent access, with initial intrusion methods also evolving beyond phishing to more tailored social engineering, including phone calls and video chats in fluent Ukrainian before malicious files are delivered through messaging apps. Agencies tied the activity to groups including APT28 and Void Blizzard, with the security and defense sector remaining the top target because disruptions there could affect the war effort.
Ukraine also confirmed a long-running cyber-espionage campaign, tracked since 2023 and attributed by Western researchers to APT28 (Fancy Bear, BlueDelta, Forest Blizzard), that targeted prosecutors, anti-corruption bodies, and other local government entities through Roundcube webmail vulnerabilities enabling code execution when a victim opened an email. Reuters reported that more than 170 email accounts belonging to prosecutors and investigators were compromised in recent months, and CERT-UA identified three waves of related attacks. Officials said some allegedly stolen material was later published online, though reviews indicated the leaks likely did not include confidential data, and warned the operation could still be used to fuel disinformation aimed at eroding trust in Ukrainian institutions.
Timeline
Apr 17, 2026
Ukraine confirms suspected APT28 campaign targeting prosecutors
Ukrainian officials publicly confirmed the long-running campaign targeting prosecutors, anti-corruption bodies, and other agencies, and said affected organizations were reviewing possible impact. The activity was described as likely useful for future Russian disinformation efforts, while some organizations said they had not found evidence of internal-system compromise or data theft.
Apr 17, 2026
Three waves of Roundcube attacks hit Ukrainian prosecutors and agencies
CERT-UA identified three waves of attacks exploiting Roundcube webmail flaws to execute malicious code when victims opened emails. Reuters reported that more than 170 email accounts belonging to Ukrainian prosecutors and investigators were compromised in recent months.
Apr 3, 2026
Ukraine warns Russia is revisiting old breaches for new attacks
CERT-UA warned that Russian hackers were attempting to regain access to systems they had previously compromised by testing whether old footholds, unpatched vulnerabilities, and stolen credentials still worked. The agency said groups including APT28 and Void Blizzard had used these methods against Ukraine's armed forces and government institutions.
Mar 1, 2026
Some allegedly stolen information is published online
Ukrainian officials said material allegedly stolen in the campaign was published online in March. They assessed that the leaked information likely did not include confidential data, but warned it could be used for disinformation purposes.
Jul 1, 2025
CERT-UA observes fewer cyber incidents in second half of 2025
Ukraine's CERT-UA reported a decline in the total number of cyber incidents during the second half of 2025. Despite the drop, the security and defense sector remained the primary target because compromises there could affect the war effort.
Jan 1, 2025
Russian hackers shift toward maintaining persistent access in Ukraine
CERT-UA said that during 2025, Russian intrusion activity increasingly focused on preserving and reusing access from earlier compromises rather than only stealing credentials quickly. The agency also observed initial access tactics evolving from traditional phishing to social engineering via phone calls, video chats, and malicious files sent through messaging apps.
Aug 1, 2023
CERT-UA links APT28 to Roundcube exploits in espionage campaign
CERT-UA published an alert describing an espionage campaign in which APT28 used three Roundcube vulnerabilities—CVE-2020-35730, CVE-2021-44026, and CVE-2020-12641. The disclosure provided early technical attribution and exploit details for activity targeting Ukrainian entities.
Jan 1, 2023
Ukraine begins tracking espionage campaign against prosecutors and agencies
Ukrainian officials said they have been tracking a cyber-espionage campaign targeting local government and law-enforcement-related entities since 2023. The activity was later linked by Western researchers to exploitation of Roundcube webmail vulnerabilities.
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