Professional services
Cybersecurity for professional services firms and the client work they hold
ACS Cyber provides managed cybersecurity and incident response for professional services firms: 24/7 monitoring of Microsoft 365, identities, and devices from our in-house SOC, help answering client security reviews, and in-house forensic investigation when something goes wrong. Start with a free 30-minute consultation, or call our 24/7 incident line if you have an active incident.
- Microsoft 365 security
- Client security reviews
- Partner and contractor access
- 24/7 security monitoring
Professional services risk
The risks we see in professional services
Consulting, engineering, architecture, marketing, and other client-service firms are trusted with other organizations’ strategies, designs, financials, and personal data. Attackers know a smaller firm can be a quieter way into a larger client.
Microsoft 365 account takeover happens when an attacker signs in with a stolen password or session and uses the account to read mail, reach files, or send convincing messages to your clients. It often starts with a phishing message that looks like a routine file share.
- Client data in many places. Proposals, deliverables, and client files live across email, SharePoint, Teams, OneDrive, and personal devices.
- Microsoft 365 sprawl. Guest accounts, open sharing links, and inconsistent settings build up over time and quietly widen exposure.
- Partner and contractor access. Freelancers, subcontractors, and partner firms often keep access long after a project ends.
- Business Email Compromise. Invoices and payment instructions flow constantly between firms and clients, which makes a compromised mailbox valuable to an attacker.
When clients ask about security
Many clients now send security questionnaires before they share data or renew a contract, and a vague answer can stall the work.
We help you understand what you can honestly say today, what to improve, and how to show the evidence behind your answers.
Have you been compromised?
If an account has been taken over, call us before it spreads
If someone signed in to an account they should not have, a phishing message led to a stolen password, or client files may have been reached, call our 24/7 incident line. We contain the account, find out what happened through in-house forensic investigation, work with your insurer and counsel when you authorize it, and help you close the gap so it does not happen again.
Fraudulent invoices sent from your domain? See BEC and wire fraud response. Client data exposed? See data breach and exposure support.
Professional services incidents we respond to
- Microsoft 365 account takeover
- Phishing and stolen passwords
- Invoice and payment fraud
- Exposed client files
- Contractor account misuse
- Ransomware
How ACS Cyber helps
Services matched to professional services risk
Each service covers a specific exposure, and one accountable team coordinates all of them.
Monitoring across Microsoft 365 and endpoints
Our in-house SOC watches sign-ins, mailbox activity, file sharing, and endpoint behavior around the clock, and investigates anything that looks like misuse.
Security leadership on demand
A virtual CISO sets priorities, writes practical policies, reviews vendors, and gives leadership a clear view of risk without a full-time hire.
Client and framework requirements
We help you prepare for client security reviews, pursue SOC 2 readiness where clients expect it, and align controls with frameworks such as the CIS Controls.
Exposure and configuration reviews
Vulnerability scanning and Microsoft 365 configuration reviews find risky settings, stale accounts, and missing patches, with remediation guidance you can act on.
Training for client-facing teams
Phishing simulations and short training on invoice fraud, impersonation, and safe file sharing, built around how your people actually work.
Incident response
If an account or device is compromised, we help contain it, investigate in-house, and give you clear findings to support communication with affected clients.
Readiness
What we help you prepare
Controls and documentation that support client reviews, insurer questions, and day-to-day protection of client work.
- Multi-factor authentication and conditional access for every account, including contractors
- A review of guest accounts, external sharing links, and Microsoft 365 security settings
- Onboarding and offboarding steps for employees, contractors, and partner firms
- A simple classification for client files, with sharing rules people can follow
- Device standards for laptops and phones that access client data
- Honest, evidence-backed answers for client security questionnaires
- Security policies and an incident response plan your leadership has reviewed
- Supporting documentation for cyber-insurance applications
Getting started
How we start
A clear path from the first conversation to a working security program.
01
Free 30-minute consultation
Talk with a cybersecurity expert about your firm, your clients’ expectations, and what concerns you most. You leave with a clear next step, whether or not we work together.
02
Assessment
We review Microsoft 365, identities, devices, sharing, and third-party access to find where client data is most exposed.
03
Roadmap
You receive a prioritized plan in business language, including the changes that will matter most in your next client security review.
04
Protect and improve
We put monitoring and controls in place, then review trends and progress with you as the firm grows.
Questions
Professional services cybersecurity questions
ACS Cyber provides managed cybersecurity and incident response for consulting, engineering, architecture, marketing, and other professional services firms nationwide. As the MSSP and cybersecurity division of Atlantic Computer Systems, we combine 24/7 monitoring from our in-house SOC with practical help on client security reviews.
Call our 24/7 incident line at 1-650-300-7557. If you can, reset the password and sign the account out of all sessions, but do not delete suspicious emails or inbox rules before they are documented, because they are evidence. We help secure the account, work to establish what was accessed through in-house forensic investigation, and support your legal counsel as they decide on any client notifications. See hacked account response for what happens next.
Answer accurately, then close the gaps the questionnaire exposes. We help you do both, so each review goes more smoothly than the last. Atlantic Computer Systems, our parent company, also offers a cybersecurity assessment that reviews identity, endpoint, email, and backup controls.
It depends on your clients and contracts. SOC 2 reports are most common for firms that host or process client data. We help you decide whether readiness work makes sense now and, if it does, prepare for the independent audit.
Give contractors only the access a project needs, protected by multi-factor authentication and reviewed regularly, and remove it cleanly when the work ends. We help you set that up and keep it current.
Yes. We review identities, sharing, mailbox settings, and security policies, then prioritize changes so they reduce risk without disrupting client work. Atlantic Computer Systems, our parent company, provides managed IT including Microsoft 365 administration, so the underlying changes can be carried through when you want that. Learn about Atlantic Computer Systems.
We complement them. Your IT lead keeps running daily operations while we provide 24/7 security monitoring, human-led investigation, and security expertise they can call on. If your IT lead also needs help with day-to-day work, Atlantic Computer Systems, our parent company, offers co-managed IT services.
Professional services security
Give clients a confident answer about security
Start with a free 30-minute consultation. We will look at how client data moves through your firm and suggest a practical next step.