MANAGED CYBERSECURITY AND INCIDENT RESPONSE
Cyber defense built for the moments that matter.
ACS Cyber helps organizations prepare for attacks, detect threats around the clock, contain active incidents, and recover with confidence. Get one accountable security partner across endpoints, identity, email, cloud, network, and users.
Dealing with an active incident? Call 1-650-300-7557 — our 24/7 incident line.
Incident response and recovery
Have you been compromised?
When an incident happens, clarity and speed matter. If you are facing ransomware, a phished account, a fraudulent payment request or exposed data, call our 24/7 incident line. We help contain the threat, find out what happened, work alongside your insurer and breach counsel on your compliance obligations, restore operations and strengthen your defenses against a repeat.
01
Contain
We help you stop the spread: isolating affected devices, disabling compromised accounts and cutting off attacker access, while preserving the evidence an investigation depends on.
02
Investigate
Our in-house forensic investigation works to establish how the attacker got in, what they accessed or took and whether they still have access, with documented evidence handling and chain of custody.
03
Coordinate
With your authorization, we coordinate with your insurer and breach counsel, work alongside any insurer-assigned response firm where your policy permits, and prepare the findings your counsel needs for notification and compliance decisions.
04
Recover
We help you restore systems, mailboxes and accounts in a controlled order, close the path the attacker used and get your team back to work.
05
Protect
We help prevent a repeat with managed detection and response from our in-house 24/7 SOC, security awareness training, vulnerability management and incident-response planning.
- Business Email Compromise
- Ransomware
- Microsoft 365 account compromise
- Malware
- Data exposure
- Unauthorized access
- Insider activity
- Suspicious financial or email activity
Not sure what you are seeing? Check the warning signs or follow our step-by-step first actions. Not a client yet? You can still call the 24/7 incident line, and if a fraudulent payment was sent, contact your bank as well. Please do not send passwords, logs or evidence files by email; once we are engaged, we arrange secure evidence handling.
24/7 Security Monitoring
Human-Led Threat Investigation
Endpoint, Identity, Email, Cloud and Network Coverage
Security Support Before, During and After an Incident
Prepare. Protect. Respond. Recover.
One security partner from preparation through recovery.
ACS Cyber is the managed security services provider (MSSP) and cybersecurity division of Atlantic Computer Systems, with an in-house 24/7 SOC. We support small and midsize organizations nationwide at every stage, so preparation shapes protection, protection makes response more focused, and every incident leaves your program stronger. The simplest way to start is a free 30-minute consultation.
01
Prepare
Risk assessments, policies, compliance readiness, security roadmaps, and tabletop exercises.
- Cybersecurity advisory and vCISO
- Risk and compliance readiness
- Incident-response planning
02
Protect
Endpoint, identity, email, cloud, network, vulnerability, and user protection.
- Managed detection and response
- Vulnerability management
- Security awareness training
03
Respond
Investigation, containment, evidence preservation, remediation guidance, and stakeholder coordination.
- 24/7 incident line
- In-house forensic investigation
- Coordination with counsel and insurers
04
Recover
Business restoration, security hardening, lessons learned, and long-term risk reduction.
- Restoration planning
- Post-incident hardening
- Lessons-learned review
Core services
Proactive protection. Decisive response.
Start with the service that matches your most pressing need. Each one connects to the others, and risk and compliance, vulnerability management and security awareness training round out the program.
Managed Detection & Response
24/7 monitoring, expert investigation, threat validation, containment support, threat hunting, and actionable reporting across the organization.
- Our in-house SOC analysts monitor and investigate around the clock
- Coverage for Microsoft 365, Google Workspace, Azure, AWS, networks and servers
- Pre-approved containment under rules agreed with you in advance
- ACS-managed EDR and a monthly report reviewed with you
Incident Response and DFIR
Rapid investigation and containment for ransomware, Business Email Compromise, compromised accounts, malware, unauthorized access, data exposure, and other disruptive events.
- A 24/7 incident line, open to clients and non-clients
- In-house forensic investigation with chain of custody
- Containment, eradication and recovery planning
- Coordination with your counsel and insurer when you authorize it
Cybersecurity Advisory and vCISO
Practical security leadership, risk assessments, policies, compliance roadmaps, security planning, tabletop exercises, and executive guidance.
- Fractional security leadership for your organization
- Risk assessments and prioritized roadmaps
- Policies, tabletop exercises and response planning
- Executive and board-level reporting
Coverage
Protection across your entire attack surface.
Attackers look for the easiest way in, whether that is an unmonitored laptop, a reused password or a vendor with more access than it needs. We bring each area into view and help you strengthen it.
Endpoints
We supply and manage the endpoint detection and response (EDR) agent, monitor laptops, desktops and servers for signs of compromise, and can isolate an affected device under rules you approve.
Microsoft 365
We watch sign-ins, mailbox rules, sharing and administrative changes, and help harden tenant settings such as multifactor authentication and conditional access.
Identity and access
We look for risky sign-ins, privilege changes and account takeover patterns, and help tighten how access is granted, reviewed and removed.
Business email
We watch for phishing, impersonation and suspicious forwarding, and help configure email authentication (SPF, DKIM and DMARC) so your domain is harder to spoof.
Cloud applications
We monitor security activity in Google Workspace, Azure and AWS, and review access and configuration for the business applications you rely on.
Networks
We bring firewall and network activity into view, and help close exposed services, separate sensitive systems and secure remote access.
Servers
We monitor on-premises and cloud servers for suspicious activity, and help prioritize patching and configuration fixes for the systems your business depends on.
Backups and recovery
We review whether backups are protected from tampering and can be restored, and help you test recovery before you need it.
Employees
We help your people recognize phishing and impersonation through training and simulations, and make it simple to report a suspicious message.
Vendors and third parties
We help you review vendor access and security practices, and limit what outside parties can reach in your environment.
Why ACS Cyber
Cybersecurity that works in the real world.
Security recommendations must work with your actual technology, people, business processes, and risk tolerance. A control that looks good on paper but breaks a workflow, or sits unmanaged, does not reduce risk.
We build programs that hold up in daily operations and under pressure. See what makes ACS Cyber different.
01
Human expertise, not alert forwarding
Our in-house SOC analysts investigate activity, confirm what is real and tell you what to do next. You do not receive a stream of raw alerts to sort through yourself.
02
Clear ownership and accountability
One security partner is responsible for monitoring, response and follow-through, so nothing falls between vendors when it matters.
03
Business-focused recommendations
We explain risk in terms of operations, cost and obligations, and prioritize the work that reduces the most risk for your organization.
04
Integrated IT and cybersecurity experience
As part of Atlantic Computer Systems, we understand the systems behind the alerts and can help remediate the underlying IT environment, not just report on it.
05
Continuous improvement and reporting
Regular reporting shows what we saw, what we did and what should change next, so your security program gets stronger over time.
Our approach
How engagement works.
Every engagement follows the same disciplined path, scaled to the size and complexity of your organization.
01
Understand
We review your business, technology, risks, obligations, and existing controls. It starts with a free 30-minute consultation and continues with a structured look at your environment.
02
Establish
We deploy or improve security controls and establish a reliable operating baseline, so normal activity is understood and meaningful activity stands out. Typical onboarding for managed detection and response takes 2-4 weeks.
03
Monitor and Respond
Our SOC investigates meaningful activity around the clock, contains threats under rules agreed with you in advance, and communicates clearly with the people you designate.
04
Improve
We review trends, remediate weaknesses, and continuously strengthen the security program with recommendations your team can act on.
Industries
Support for regulated and security-sensitive organizations.
Many of the organizations we work with handle information that clients, patients and regulators expect to be protected. We understand the obligations and the day-to-day pressures that come with that responsibility.
Healthcare
Protecting patient information, clinical workstations and Microsoft 365 environments, with readiness support for the HIPAA Security Rule, including its risk analysis requirement.
Legal
Safeguarding privileged communications and matter files, and defending against the email impersonation and payment fraud that target firms and their clients.
Accounting and Financial Services
Securing client financial data and busy-season workflows, and helping you prepare a written information security plan aligned with the FTC Safeguards Rule and IRS Publication 4557.
Professional Services
Protecting client data and your reputation, answering client security questionnaires with confidence, and securing remote and hybrid teams.
Multi-Location Businesses
Applying consistent security across sites, networks and users, with central visibility and one security partner for every location.
Regulated Organizations
Readiness, control alignment and evidence preparation for frameworks such as CMMC, NIST SP 800-171, PCI DSS and SOC 2, along with cyber-insurance requirements.
Atlantic Computer Systems
Backed by real-world IT operations.
ACS Cyber is the cybersecurity division of Atlantic Computer Systems and combines specialized security expertise with a practical understanding of Microsoft 365, endpoints, networks, cloud services, business continuity, and day-to-day IT operations.
Atlantic Computer Systems provides managed IT solutions, including helpdesk support, Microsoft 365 administration, cloud, networks, VoIP and IT logistics. When we find a security risk, the fix can be carried through in the underlying IT instead of handed off to someone else. Organizations that keep their own IT staff can also add co-managed IT support from Atlantic Computer Systems.
ACS Cyber is headquartered in San Jose, California, with an office hub in Boston, supporting organizations nationwide. Atlantic Computer Systems, our parent company, also provides nationwide remote IT support.
Managed IT from Atlantic Computer Systems
- Helpdesk support
- Microsoft 365 administration
- Cloud services
- Networks
- VoIP
- IT logistics
Insights
Practical guidance from our security team.
Guidance on incident response, Microsoft 365 security, Business Email Compromise prevention and cyber-insurance readiness, written for the people who make security decisions. Browse all resources.
A Microsoft 365 security baseline for small and midsize organizations
The Microsoft 365 security settings we review most often, from MFA and Conditional Access to admin roles, email authentication, sharing and backup, plus what to do if an account is already compromised.
Executive Cybersecurity Education
EDR vs. MDR: what each one does and which your organization needs
EDR is a technology and MDR is a service; this guide explains what each one does, where EDR alone falls short and how to decide which fits your organization.
Cyber-insurance readiness: the controls underwriters commonly ask about
The security controls cyber-insurance applications commonly ask about, how to answer accurately, the evidence worth keeping, and how to work with your insurer if an incident happens.
Questions
Common questions about ACS Cyber.
ACS Cyber is the managed security services provider (MSSP) and cybersecurity division of Atlantic Computer Systems, with an in-house 24/7 SOC. We provide managed detection and response, incident response and DFIR, cybersecurity advisory and vCISO, risk and compliance readiness, vulnerability management with in-house penetration testing, and security awareness training.
We are headquartered in San Jose, California, with an office hub in Boston, supporting organizations nationwide. You can also read background on Atlantic Computer Systems, our parent company.
ACS Cyber provides 24/7 security monitoring for small and midsize organizations through managed detection and response, delivered by our own in-house SOC analysts rather than a third party.
We supply and manage the EDR agent, monitor Microsoft 365, Google Workspace, Azure and AWS along with firewall, network and server activity, and take pre-approved containment actions, such as isolating a device or disabling an account, under rules agreed with you in advance.
Isolate affected systems and bring in an incident response team before you wipe, rebuild or restore anything, so evidence is preserved and the attacker’s access is understood first. To isolate a device, disconnect it from the network rather than powering it off where you can, and keep backups disconnected so they are not encrypted too.
If you have cyber insurance, notify your insurer and your legal counsel promptly, because your policy may specify which response firms you can use. You can also report the attack to the FBI Internet Crime Complaint Center (IC3) or CISA.
The ACS Cyber 24/7 incident line, 1-650-300-7557, is open to clients and non-clients. See ransomware response for what to do first.
Yes. Non-clients can call our 24/7 incident line at 1-650-300-7557 for help containing the threat, investigating what happened and planning recovery.
If you have cyber insurance, notify your insurer as well. We work alongside insurer-assigned response firms where your policy permits, and coordinate with your legal counsel when you authorize it. See how we help after a compromise, including business email compromise and wire fraud, hacked email and Microsoft 365 accounts and data exposure.
Book a free 30-minute consultation with a cybersecurity expert to talk through your environment, obligations and priorities. For an active incident, call the 24/7 incident line instead.
If you choose managed detection and response, typical onboarding takes 2-4 weeks, depending on the size and complexity of your environment.
Free 30-minute consultation
Strengthen your security before the next incident.
Whether you need continuous monitoring, a security roadmap, or immediate incident support, ACS Cyber can help you understand the risk and take the next step.