Publicly traded vulnerability detection provider Tenable Inc. will pay $98 million to buy Paris-based Alsid SAS, which makes software for finding security issues in Active Directory deployments.

In the acquisition announcement today, Tenable said that it expects the deal to close early next quarter. The company anticipates $3 million to $4 million in acquisition-related expenses and estimates the transaction will become accretive to its free cash flow next year.

Tenable, based in Columbia, Maryland, sells vulnerability detection products that companies use to find security issues in their systems. A security issue can be an application containing a library with a known exploit, or it can be a configuration problem such as a weak password. Tenable has north of 30,000 customers globally including more than half the Fortune 500.

Alsid, too, competes in the vulnerability detection segment but has a narrower focus on Active Directory deployments. Active Directory is a Microsoft Corp. service ubiquitous in the enterprise that is used to process employee login requests to work applications. Consequently, it’s a big target for hackers. Compromising the service can enable an attacker to hijack user accounts with access to important systems.

Alsid’s software helps enterprises detect weak points in their Active Directory deployments before hackers do. The software spots user accounts that aren’t actively in use but could be exploited for attacks, insecure passwords, misconfigurations and other issues. Alsid also provides a complementary tool for detecting breach attempts. 

A notable detail is that Alsid’s products don’t have to install software agents in Active Directory deployments to find threats. That simplifies the initial setup, a plus for administrators, and also lowers risk because the lack of software agents means there are fewer moving parts hackers could potentially target.

“Attackers go after the Active Directory infrastructure to increase access and establish persistence,” said Tenable Chief Executive Amit Yoran. “We’re impressed with the insights that Alsid brings to enterprise customers and look forward to working with the Alsid team to add this critical element to Cyber Exposure and risk management.” Cyber Exposure is Tenable’s flagship vulnerability detection platform.

In an explainer for shareholders, the company provided additional details about the reasoning behind the deal. Alsid sells its software to big enterprises, which Tenable says aligns with its go-to-market strategy. Enterprises have large Active Directory deployments managing many users across multiple locations, complexity that increases the need for security automation.

Companies still mostly run Active Directory on-premises, Tenable noted. Alsid works with both on-premises and cloud deployments, which will enable Tenable to protect its customers’ existing infrastructure while at the same time supporting their cloud migration initiatives. 

Alsid founders Emmanuel Gras and Luc Delsalle will join the company in senior leadership roles to shape its strategy for the Active Directory security market. Alsid has about 100 employees in total. 

Photo: Tenable