Cybersecurity partner
Passguard
The S-Unit expands penetration testing and red teaming with Passguard infostealer intelligence
UTRECHT, 1 September 2026 – Offensive security specialist The S-Unit and infostealer specialist Passguard have entered into a strategic partnership. By integrating Passguard’s infostealer intelligence into services including penetration testing and red teaming, The S-Unit can now test attack scenarios in which initial access is gained through credentials and session tokens stolen by infostealers. sessietokens.
Infostealers as a growing initial access risk
Stolen credentials play a significant role in cyberattacks. According to the IBM X-Force Threat Intelligence Index 2025, attackers used valid account credentials for initial access in 30% of the incident response cases examined.
Infostealers are one of the ways these credentials end up in the hands of attackers. This type of malware steals login credentials, cookies and active session tokens. The stolen data is then bundled into so-called infostealer logs and can be traded through dark web marketplaces and criminal channels. Attackers can subsequently use this data to gain access to corporate environments.
Marko van Zwam, Managing Director of The S-Unit, explains: “Preventing initial access is a crucial step in cybersecurity. Attackers are increasingly using access obtained through infostealers. With Passguard’s intelligence, we can now validate and simulate this form of initial access in a controlled manner.”
Infostealer data as part of offensive security
As part of the partnership, The S-Unit is adding Infostealer Credential Testing to its offensive security services. This makes it possible to determine whether access to an organisation has been compromised by infostealers and what an attacker could achieve with that access in practice.
Tom Leijte, CEO of Passguard, says: “If you think like an attacker, you need to be able to work with the access an attacker actually has. Stolen credentials and sessions are increasingly part of that reality. By combining our intelligence with The S-Unit’s offensive security expertise, they can now incorporate this real-world threat into penetration testing and red teaming.”
An ethical approach at the core
The ethical approach of both organisations is also an important part of the partnership. Nick Bruinsma, Lead Red Teamer at The S-Unit, says: “Passguard operates according to a fully ethical methodology that aligns with our own strict standards. This allows us to help organisations mitigate this risk without compromising our ethical principles.”
About Passguard
Passguard is a Dutch dark web monitoring platform specialising in infostealer malware. The company monitors stolen login credentials, cookies and active session tokens in real time, giving organisations early visibility into compromised access. Passguard serves hundreds of organisations worldwide, including AFAS Software, Damen Shipyards and Royal FloraHolland. passguard.com.
About The S-Unit
The S-Unit is a Dutch cybersecurity company specialising in offensive security. Since 2014, its team of more than 25 certified security specialists has helped organisations strengthen their digital resilience through penetration testing, red teaming, social engineering, strategic security consulting and training.
Want to learn more about Passguard’s infostealer intelligence in penetration testing and red teaming? Get in touch.
