Limerston Capital announces further investment in cyber services platform, Xypher, with Aristi acquisition
- Dieter Joseph
- Dec 3
- 3 min read
UK mid-market private equity firm Limerston Capital today announces the addition of Aristi, a highly accredited UK penetration testing and cyber security consultancy, to its cyber security platform, Xypher. This transaction is the third in 6 months and builds on the group’s momentum as it continues its strategy to expand through both organic growth and strategic acquisitions, with the ambition to become one of the UK’s most trusted leaders in cyber security, digital forensics, case management and e-Discovery services.
Aristi joins CyberCrowd, DigitalXRAID and IntaForensics as part of Xypher, the Limerston backed UK-based cyber services leader, with expertise in compliance, penetration testing, managed SOC, incident response, digital forensics and e-Discovery.
The acquisition significantly enhances Xypher’s existing capabilities across cyber consultancy, penetration testing, and incident readiness, while adding greater depth in operational technology (OT) security and public sector engagement. Combined, Xypher offers comprehensive end-to-end cyber resilience services for organisations across the public and private sectors, including those operating within the UK’s critical national infrastructure and national security domains.
It also reinforces the group’s position as an attractive destination for specialist cyber talent.
Martim Avillez, Founding Partner at Limerston Capital, commented:
“Aristi is an outstanding addition to our cyber security platform Xypher which is growing rapidly through our buy-and-build strategy with three acquisitions within 6 months. Their NCSC CHECK and CREST accredited penetration testing team, alongside their strong governance and consultancy services, strengthens the group’s ability to deliver high-assurance cyber security to organisations operating in complex and regulated environments.
What impressed us most is Aristi’s long-standing reputation for quality, integrity and partnership-led delivery. We’re excited to support Harj and the team as they scale and continue to deliver exceptional outcomes for clients across the UK as demand for cyber security services increases rapidly.”
Harj Singh, Chief Executive Officer of Aristi, added:
“Joining Limerston Capital’s cyber security platform represents a significant milestone for Aristi and the next natural step in our growth journey. Over the last 17 years, we’ve built a business grounded in technical excellence, trusted accreditations, and long-term customer relationships. This acquisition gives us the capacity and investment to broaden our capabilities, strengthen our delivery, and expand into areas that will bring even greater value to our customers.
Limerston’s vision for the group reflects our own ambition to provide high-assurance cyber security services to organisations that rely on resilience and trust. We look forward to working with Limerston Capital to unlock a wider range of services that support our clients’ evolving needs.”
For more information, please contact:
Martim Avillez martim.avillez@limerstoncap.com +44 (0)203 897 1860
Media:
Caroline Villiers cvilliers@keplercomms.com +44 (0)7808 585184
Charlotte Balbirnie cbalbirnie@keplercomms.com +44 (0)7989 528421
About Limerston Capital
Founded in 2015 by James Paget, João Rosa and Martim Avillez, London based Limerston Capital pursues control investments in UK mid-market companies and seeks to create value through the firm’s buy-and-build and operationally focused model. The firm targets businesses with EBITDA of between £5 million and £15 million that have a solid value proposition, but have potential for operational improvements, have mispriced underlying returns on capital and provide opportunities for strategic repositioning via consolidation.
About Xypher
Xypher is a group of UK-based cyber security, digital forensic investigation and e-Discovery specialists with more than a decade of experience and extensive certified expertise, brought together to deliver industry leading end-to-end protection for organisations that demand excellence. From Managed Security Services and Incident Response to Digital Forensics, e-Discovery, Forensic Case Management, Compliance and Consultancy, we combine deep expertise with cutting-edge capability.
About Aristi
Aristi is one of the UK’s leading providers of penetration testing services with over 17 years of experience, supporting clients in the public and private sectors. We are a National Cyber Security Centre (NCSC) approved CHECK penetration test company and our testing services are also accredited by CREST. We provide a range of security testing services to help protect your cyber defenses, as well as Information Assurance support and training.