No. Antivirus is still worth having, but antivirus alone is not enough to protect business data. It catches known malicious files, and most attacks today do not use one.
79% of attacks to gain initial access are now malware-free (CrowdStrike 2025 Global Threat Report). Attackers sign in with stolen passwords and use tools that are already on the computer. There is no bad file for antivirus to find.
Here is what antivirus does well, where it falls short, and what a small business needs on top of it.
How Antivirus Works
Antivirus compares the files on a computer against a list of known malicious files. When it finds a match, it quarantines the file. Real-time scanning checks files the moment they open, which is a big improvement over scheduled scans.
But the method has one limit that no feature fixes: antivirus can only stop what it recognizes as a bad file.
What Antivirus Still Catches
Good business antivirus still does useful work against file-based threats:
- Viruses: malicious code hidden in attachments, downloads or shared files
- Spyware: software that collects passwords and personal data
- Adware: software that tracks browsing and can carry spyware with it
- Other known malware: trojans, worms and similar threats
That is why we keep it. It is one layer, not the whole wall.
Antivirus Disadvantages For Business
Most Attacks Do Not Use Malware Files
Fileless attacks run in memory or use built-in tools like PowerShell. With 79% of initial access attacks now malware-free (CrowdStrike, 2025), a file scanner misses most of the front door.
Stolen Passwords Walk Straight Past It
Use of stolen credentials was the top hacking method in small and medium business breaches, at 33% (Verizon 2025 Data Breach Investigations Report, SMB Snapshot). When an attacker signs in to Microsoft 365 with a real password, antivirus on the laptop never sees it.
Phishing Links Are Not Files
Most phishing emails carry a link to a fake sign-in page, not an attachment. Antivirus has nothing to scan. Teach your team how to identify phishing emails.
It Cannot Bring Your Data Back
Ransomware was involved in 88% of breaches at small and medium businesses (Verizon 2025 DBIR, SMB Snapshot). Antivirus has no recovery tools. Once files are encrypted, only a backup brings them back. See how our backup and recovery services restore your data.
It Does Not Stop People With Too Much Access
Mistakes and misuse from inside the business are a real risk. Read more about insider threats. Antivirus does not control who can open which files.
What Small Businesses Need On Top Of Antivirus
Endpoint Detection And Response (EDR)
EDR watches behaviour, not just files. It spots a normal tool doing something abnormal, isolates the computer and alerts a person to respond. See our managed EDR and MDR services and how endpoint management works.
Identity Protection: MFA And Conditional Access
Since attackers sign in instead of breaking in, protect the sign-in. Multi-factor authentication and Conditional Access check who is signing in, from which device and from where. Learn how to protect business email and cloud accounts and read our identity and access management guide.
No Admin Rights For Everyday Work
Staff work on standard accounts. When malware runs without admin rights, it cannot install itself across the computer. Read why sharing admin rights with your IT company is safer than giving them to everyone.
Automatic Patching
Attackers use known security holes that already have a fix. Keep Windows, macOS, browsers and business apps updated automatically, on a schedule your IT team checks.
Backup Of Microsoft 365 And Your Files
Back up every mailbox, OneDrive, SharePoint site and Teams, and test that you can restore them. A tested backup turns ransomware from a disaster into a bad day. See our backup and recovery services.
Email Authentication
SPF, DKIM and DMARC stop criminals from sending email that looks like it came from your domain. They also help your real email reach the inbox.
Security Awareness Training
Your team is the last check before a click. Short, regular cyber awareness training helps them spot phishing and report it.
Protect Your Toronto Business With Layers, Not One Tool
Each layer covers a gap in the others. That is a defense in depth strategy, and it is how we protect small businesses across Toronto and Durham Region. Antivirus stays in the stack. EDR, identity protection, patching and backup do the rest, managed by the same team that knows your people and your setup.
Explore our cybersecurity services.
Antivirus FAQ
Is antivirus alone enough for a small business?
No. Antivirus catches known malicious files, but most attacks today use stolen passwords and tools already on the computer. A small business needs EDR, identity protection, automatic patching and a tested backup on top of it.
Do I still need antivirus if I have EDR?
Most EDR products include antivirus scanning, so you get both in one tool. You do not need a second, separate antivirus product.
Is Microsoft Defender Antivirus enough for a small business?
Defender Antivirus is built into Windows and is a good antivirus layer. On its own it is still antivirus. Microsoft Defender for Business, included in Microsoft 365 Business Premium, adds EDR and central management.
Can antivirus stop ransomware?
It can stop some known ransomware files. It cannot stop an attacker who signs in with a stolen password, and it cannot restore encrypted files. You need EDR, identity protection and a tested backup.
