Semperis adds detection for dMSA attacks in Windows Server

Semperis has announced new detection capabilities in its Directory Services Protector platform in collaboration with Akamai to address the "BadSuccessor" privilege escalation technique in Windows Server 2025.

BadSuccessor targets a new Windows Server 2025 feature called delegated Managed Service Accounts (dMSAs), which was designed to improve service account security. Researchers at Akamai have shown that attackers can exploit dMSAs to impersonate highly privileged users, such as Domain Admins, within Active Directory. At present, there is no patch available to address this vulnerability.

Service accounts, including dMSAs, often operate with extensive or unmonitored privileges, creating potential security risks for enterprises. The exploitation method uncovered by Akamai highlights ongoing challenges in securing service accounts and preventing unexpected attack vectors within large organisations.

In response, Semperis has updated its Directory Services Protector platform to include one new Indicator of Exposure and three Indicators of Compromise aimed at detecting abnormal dMSA activity. These enhancements will enable security teams to identify excessive delegation rights, malicious connections between dMSAs and privileged user accounts, and attacks directed at sensitive accounts such as KRBTGT.

"Semperis moved quickly to translate the vulnerability into real-world detection capabilities for defenders, demonstrating how collaboration between researchers and vendors can lead to rapid, meaningful impact. The abuse of service accounts is a growing concern, and this high-profile vulnerability is a wake-up call," said Yuval Gordon, Security Researcher at Akamai.

"Service accounts remain one of the least governed yet most powerful assets in enterprise environments. This collaboration with Akamai allowed us to close detection gaps fast and give defenders visibility into a deeply complex area of Active Directory that attackers continue to exploit," said Tomer Nahum, Security Researcher at Semperis.

The vulnerability is present in any organisation that operates at least one domain controller running Windows Server 2025. According to Semperis, a single misconfigured domain controller can place the entire environment at risk. Until vendors release an official patch, organisations are encouraged to audit dMSA permissions and use detection tools to monitor for misuse.

Semperis is reinforcing cybersecurity for enterprises by protecting critical identity services that underpin hybrid and multi-cloud environments. Purpose-built for securing complex identity infrastructures — including Active Directory, Entra ID, and Okta — Semperis' AI-powered platform safeguards more than 100 million identities from cyberattacks, data breaches, and operational missteps.

Headquartered in Hoboken, New Jersey, the privately held international company supports major global brands and government agencies, with customers spanning over 40 countries.

Beyond its core technology offerings, Semperis is recognized for its commitment to the cybersecurity community. The company sponsors a range of industry resources, including the award-winning Hybrid Identity Protection (HIP) Conference, the HIP Podcast, and free identity security tools such as Purple Knight and Forest Druid.

With its dual mission to protect digital infrastructure and empower the security community, Semperis continues to play a pivotal role in advancing global cyber resilience.