There is a ghost inside your business.

It may be sitting quietly inside a laptop, desktop, server or mobile device. It may not lock your files, flash a warning or announce its presence. Instead, it watches, waits and quietly sends information elsewhere.

This is the danger of a compromised endpoint. The device may still appear to work normally while an attacker uses it to steal credentials, access Microsoft 365, move through your network or prepare a ransomware attack.

As we head into Halloween, it is a useful reminder: the most dangerous threat is often the one you cannot see.

The good news is that modern endpoint security solutions can uncover these hidden intruders before they become a business-critical incident.

Could your business laptop already be compromised?

An endpoint is any device that connects to your business systems or data, including:

• Laptops and desktop computers
• Mobile phones and tablets
• Servers
• Remote-working devices
• Point-of-sale systems and other connected equipment

The UK Government’s Cyber Security Breaches Survey 2025/2026 found that 46% of small businesses reported experiencing a cyber security breach or attack in the previous 12 months. However, smaller organisations may also be less likely to identify attacks because they often have fewer monitoring tools and less specialist expertise.

That means the absence of an obvious incident does not necessarily mean your business is safe.

Warning signs you should not ignore

A single symptom may have an innocent explanation. Several symptoms appearing together deserve immediate investigation.

1. Unusual logins and account activity

Have you noticed:

• Logins at unusual times, such as the middle of the night?
• Sign-ins from countries where your business has no staff?
• Repeated failed login attempts?
• A user accessing systems they do not normally need?
• New administrator accounts or unexpected privilege changes?

These may indicate stolen credentials or an attacker attempting to escalate their access.

Microsoft identifies unusual sign-in attempts, privilege irregularities and changes to system configurations as important Indicators of Compromise (IoCs). These are digital clues suggesting that an attack may already have taken place.

2. Sluggish performance and unexplained instability

A compromised device may become:

• Noticeably slower
• Prone to freezing or crashing
• Unusually hot, even when not under heavy use
• Slower to open applications or connect to the internet
• Subject to unexplained restarts

Malware may be using processing power in the background, scanning files, communicating with an attacker or preparing data for theft.

Of course, ageing hardware and legitimate software updates can cause similar symptoms. That is why performance issues should be considered alongside other warning signs rather than dismissed automatically.

3. Unexpected pop-ups, browser redirects or unfamiliar software

Be cautious if users report:

• Pop-ups appearing when no browser is open
• Search results being redirected
• New toolbars or browser extensions
• Unfamiliar applications or files
• Security warnings that do not look genuine
• Changes to the homepage or browser settings

Unexpected software installations and configuration changes are common signs that a device may no longer be under your organisation’s control.

4. Disabled antivirus or changed security settings

Attackers often try to weaken a device before carrying out their next action.

Look for:

• Antivirus or endpoint protection being disabled
• Logging switched off
• New exclusions added to security software
• Firewall settings changed
• Security updates being blocked
• Users suddenly receiving administrator rights

Treat unexplained security changes as a high-priority warning. Do not simply switch the protection back on and assume the problem is solved. The attacker may still have access, or may have created another way to return.

5. Night-time network activity

Your business has normal patterns of network traffic. A laptop used during office hours should not suddenly transfer large amounts of data at 2:00 am.

Suspicious activity may include:

• Regular outbound connections while the device is not in use
• Large unexplained uploads
• Connections to unfamiliar domains or IP addresses
• Repeated small connections, sometimes known as beaconing
• Unusual DNS requests
• Data being compressed or moved into unexpected folders

These patterns may indicate command-and-control (C2) communication or data exfiltration.

Why do SMEs miss the ghost?

Small and medium-sized businesses often miss compromised endpoints for practical reasons, not because they are careless.

Common barriers include:

• No dedicated security specialist
• Reliance on basic antivirus alone
• Remote devices operating outside the office
• Alerts that nobody has time to investigate
• Staff assuming strange behaviour is a hardware problem
• Out-of-date software and inconsistent patching
• No complete inventory of business devices
• A belief that attackers only target large organisations

The result is a dangerous legacy approach: wait until something breaks, then investigate.

Modern cyber security requires the opposite. You need to monitor continuously, identify anomalies early and contain suspicious devices before the threat spreads.

What do endpoint security solutions actually do?

What is it?

Endpoint security solutions protect individual devices and provide visibility into what happens on them. They combine prevention, detection, investigation and response rather than relying on a single antivirus scan.

The most important component is often Endpoint Detection and Response (EDR).

Traditional antivirus may ask:

“Is this file known to be malicious?”

EDR asks:

“Does this sequence of behaviour look like an attack?”

That distinction matters because modern attackers increasingly use legitimate tools, stolen accounts and fileless techniques to avoid detection.

How does it work?

A modern endpoint security platform can:

1. Collect telemetry
   It records relevant activity, including process launches, file changes, registry modifications, sign-ins and network connections.

2. Build a picture of normal behaviour
   It learns what typical activity looks like for a particular device, user or business environment.

3. Identify suspicious behaviour
   It can detect unusual combinations, such as a newly installed programme creating persistence, launching a script and connecting to an unfamiliar external service.

4. Alert the right people
   High-risk activity is prioritised so it does not disappear among low-value notifications.

5. Contain the threat
   A compromised endpoint can be isolated from the network, suspicious processes stopped and malicious files quarantined.

6. Support investigation and recovery
   Security teams can review what happened, how the attacker entered and whether other devices were affected.

The essential layers of modern endpoint protection

Effective endpoint security solutions should form part of a wider, layered strategy.

EDR and behavioural detection

EDR monitors activity continuously and looks for attack patterns rather than relying only on known malware signatures. It can help detect:

• Credential theft
• Suspicious PowerShell or scripting activity
• Ransomware-like file encryption
• Privilege escalation
• Lateral movement between devices
• Persistence mechanisms
• Unusual outbound connections

Automated patching

Unpatched operating systems, browsers and applications create openings attackers can exploit.

A robust patching process should:

• Identify missing updates
• Prioritise critical vulnerabilities
• Deploy patches consistently
• Report failed or missed updates
• Prevent devices from quietly falling out of compliance

Zero-trust access controls

Zero Trust means never automatically trusting a user or device simply because it is inside your network.

Endpoint controls should include:

• Multi-Factor Authentication (MFA)
• Least-privilege access
• Removal of unnecessary local administrator rights
• Device health checks
• Conditional access policies
• Network segmentation
• Restrictions on unapproved applications and removable media

Device-level controls

Your security strategy must follow your people wherever they work. Device-level controls can enforce:

• Encryption
• Secure configuration baselines
• Web and DNS filtering
• Firewall policies
• Application controls
• USB restrictions
• Mobile Device Management (MDM)
• Remote lock and wipe capabilities

24/7 SOC monitoring

Even the best technology needs someone to interpret the warning signs.

A 24/7 Security Operations Centre (SOC) can monitor alerts outside normal working hours, investigate suspicious activity and isolate affected devices quickly. This is particularly valuable for SMEs that cannot justify building an in-house security team.

Our case study on 24/7 SOC monitoring shows how continuous monitoring can stop a phishing attempt before it develops into a serious breach.

What could one compromised device cost your business?

There is no single official UK figure for the cost of one compromised laptop. The final impact depends on what the device can access, how long the attacker remains undetected and whether data or credentials are stolen.

However, the UK Government’s 2025/2026 survey provides a useful warning. Among micro and small businesses that experienced a breach with an outcome, the median perceived cost was £560. The top 10% of these cases reached £10,000, while the top 5% exceeded £14,000.

Those figures represent the wider incident, not just the device itself. A single compromised endpoint can trigger costs such as:

• Emergency investigation and incident response
• Device replacement or reinstallation
• Password resets across the organisation
• Lost staff time
• Business interruption
• Fraudulent payments
• Data protection advice
• Customer communication
• Reputational damage
• Recovery from ransomware or data loss

The laptop may be the starting point, but the financial consequences can extend across your entire business.

What should you do if you suspect a compromised endpoint?

Do not delete files, wipe the device or carry on working as normal.

Instead:

1. Disconnect or isolate the device from Wi-Fi and your business network, where safe to do so.
2. Contact your IT or security provider immediately.
3. Record what happened, including suspicious messages, times, pop-ups and recent downloads.
4. Avoid making unnecessary changes that could destroy evidence.
5. Reset affected credentials from a known-clean device, especially email, administrator and financial accounts.
6. Check other endpoints for similar activity.
7. Review your backups and incident response plan.

The NCSC guidance for infected devices provides further practical advice for sole traders and small organisations.

Do not let the ghost go unnoticed

A compromised endpoint does not need to look frightening. It may simply be slower than usual, show an unfamiliar pop-up or connect to a system at the wrong time.

That is why proactive protection matters.

At Stevens I.T. Solutions, we help businesses move from legacy, reactive IT to modern, continuously monitored protection. From EDR, patching and zero-trust controls to 24/7 SOC monitoring, we make complex technology simple and stress-free.

You can begin with a professional vulnerability assessment to uncover where your current defences may be weakest.

Do not wait for the ghost in the machine to reveal itself through a service disruption or data breach. Contact Stevens I.T. Solutions today and fortify your business with ease.