An infostealer does not need your password. It grabs the entire browser profile in one shot: saved logins, session cookies, autofill data, crypto wallet extensions, then ships them to a command-and-control server. By the time you notice, the attacker has already logged into your accounts using your own session, no MFA prompt in sight. Families like RedLine, Vidar, Raccoon, LummaC2, and StealC now account for the majority of credential theft on Windows, and the usual “just use strong passwords” advice does nothing to stop them. We compared eight anti-malware tools that specifically address the infostealer attack chain, not just generic virus scanning.
What to look for in anti-infostealer protection
The threat is narrow and the defense has to match. Watch for:
- Behavior-based detection, not just signatures. New stealer builds appear daily; a scanner that only recognizes known samples will miss most active campaigns.
- Browser data protection. Real anti-infostealer tools guard access to browser credential stores (DPAPI on Windows, Keychain on macOS) and flag any process that tries to read them.
- Session cookie isolation. Some suites run banking or work logins inside a hardened browser instance so the cookies never touch the general Chrome or Edge profile.
- Clipboard hijacker detection. Stealers often replace copied crypto addresses with attacker-controlled ones. A dedicated clipboard monitor catches this.
- Tamper protection. If an attacker can silently disable the antivirus, the antivirus is useless. Modern tools lock their own settings and processes.
- Cross-platform coverage. Infostealers targeting macOS (Atomic Stealer, MacStealer) have grown fast since 2024; the days of “Macs don’t need it” are over.
Quick comparison
| App | Best for | Free plan | Starting price/year | Platforms |
|---|---|---|---|---|
| Avast One | Free baseline with browser protection | Full free tier | $50.28 (Premium) | Windows, macOS |
| Malwarebytes Premium | Behavior detection against new stealer builds | Free scanner only | $44.99 | Windows, macOS |
| Bitdefender Total Security | Isolated Safepay browser | 30-day trial | $49.99 | Windows, macOS |
| Kaspersky Plus | Safe Money mode + password vault | 30-day trial | $54.99 | Windows, macOS |
| Emsisoft Anti-Malware | Dual-engine credential-theft heuristics | 30-day trial | $39.95 | Windows |
| Sophos Home Premium | Cloud sandbox for unknown files | Basic free tier | $44.99 | Windows, macOS |
| HitmanPro.Alert | Runtime protection layered over another AV | 30-day trial | $34.95 | Windows |
| Microsoft Defender | Baseline built into Windows 11 | Included with Windows | Included | Windows |
The apps
1. Avast One, best free baseline with browser protection
Avast One is the tool the recent Softonic coverage highlighted, and for good reason: even on the free tier, it protects browser stored data and flags suspicious credential-access attempts, not just known malware signatures. The free version bundles a small VPN allowance and a data-leak monitor that emails you when your address appears in a breach.
Where it falls short: The upsell prompts to the paid tier are frequent. Avast’s ad experience on free has softened since the Gen Digital era but is still more than Malwarebytes shows.
Pricing:
- Free: Real-time protection, browser guard, breach alerts.
- Paid: Avast One Premium at about $50.28/year covers up to 5 devices and lifts the VPN cap.
Platforms: Windows, macOS.
Download: Avast.com
Bottom line: The default choice if you refuse to pay and want something better than raw Defender.
2. Malwarebytes Premium, best behavior detection
Malwarebytes Premium built its reputation on catching malware that other engines miss, and its detection layer is tuned aggressively toward the behaviors infostealers use: reading DPAPI-protected browser credentials, dumping cookies from disk, injecting into browsers, and reaching out to freshly registered C2 domains. Its free scanner is a useful second opinion, but the real-time protection you actually want is behind the paid tier.
Where it falls short: Malwarebytes is a companion, not a full internet security suite. There’s no VPN, no password manager, no parental controls. If you want one app for everything, look elsewhere.
Pricing:
- Free: On-demand scanner only.
- Paid: Premium at $44.99/year per device, or $99.99/year for 5 devices.
Platforms: Windows, macOS.
Download: Malwarebytes.com
Bottom line: The strongest single-app pick if the only thing you care about is stopping stealers.
3. Bitdefender Total Security, best isolated browser
Bitdefender Total Security ships Safepay, a hardened Chromium instance that isolates banking and account-recovery sessions from the rest of the system. Cookies created inside Safepay stay inside Safepay, so a stealer running in your regular Chrome profile can’t harvest them. The anti-tracker component blocks the browser fingerprinting techniques stealer campaigns use to fingerprint infected hosts.
Where it falls short: The performance impact on older machines is noticeable, and Safepay only works if you actually remember to open it before logging in.
Pricing:
- Free: 30-day trial of the full suite.
- Paid: Total Security at $49.99/year for the first year, renewing higher.
Platforms: Windows, macOS.
Download: Bitdefender.com
Bottom line: The pick if you do sensitive work (banking, admin consoles) from the same machine you browse casually.
4. Kaspersky Plus, best for banking sessions
Kaspersky Plus works similarly to Bitdefender’s Safepay through its Safe Money feature, and its password vault syncs across devices with strong client-side encryption. The scan engine is competitive with any of the top three and its behavioral heuristics have historically been strong against Eastern European stealer families.
Where it falls short: Regulatory pressure has made Kaspersky harder to buy in the U.S. market (it was formally banned from federal use in 2024). If you’re in the U.S. this raises legitimate policy questions, even if the product itself performs well.
Pricing:
- Free: 30-day trial.
- Paid: Kaspersky Plus at $54.99/year for 3 devices.
Platforms: Windows, macOS.
Download: Kaspersky.com
Bottom line: Strong product, but check your local guidance before deploying in a work context.
5. Emsisoft Anti-Malware, best dual-engine coverage
Emsisoft Anti-Malware runs two scan engines in parallel (Bitdefender’s plus its own) and layers behavior blocking specifically tuned for credential-theft patterns. The company posts detailed writeups on new stealer families as they appear, which is a decent signal that the detection stays current.
Where it falls short: Windows only. No macOS, no Linux. The interface is dense and assumes some technical background.
Pricing:
- Free: 30-day trial.
- Paid: $39.95/year for one device, $59.95/year for three.
Platforms: Windows.
Download: Emsisoft.com
Bottom line: The choice for Windows power users who want the best raw detection.
6. Sophos Home Premium, best cloud sandbox
Sophos Home Premium sends suspicious files to the cloud for sandboxed analysis before they run, which catches novel stealer builds that pure on-device signatures would miss. Its web protection blocks the tracker networks that drive-by download campaigns use as delivery infrastructure.
Where it falls short: The Home version is stripped down from Sophos’s enterprise product; some of the advanced policy controls you might expect are absent. Support is thin compared with Malwarebytes.
Pricing:
- Free: Sophos Home Free with limited protection.
- Paid: Home Premium at $44.99/year for up to 10 devices.
Platforms: Windows, macOS.
Download: Sophos.com
Bottom line: The value pick if you protect a small household of mixed Windows and Mac machines.
7. HitmanPro.Alert, best runtime protection layer
HitmanPro.Alert is designed to sit alongside a primary antivirus, not replace it. Its CryptoGuard component blocks ransomware, its browser protection specifically hardens Chrome and Firefox against process injection, and its kernel-level anti-exploit layer catches the memory-corruption techniques stealer loaders use to bypass Defender. Small footprint, low friction.
Where it falls short: Windows only. Some of the more aggressive protections can conflict with legitimate developer tools that inject into browsers.
Pricing:
- Free: 30-day trial.
- Paid: $34.95/year for one device.
Platforms: Windows.
Download: Sophos.com/HitmanPro
Bottom line: Add this on top of Defender or Malwarebytes for an extra runtime layer, not as a standalone.
8. Microsoft Defender, best free baseline for Windows
Microsoft Defender is what runs on your Windows 11 machine right now unless you explicitly installed something else. It has caught up substantially over the last three years, and the combination of SmartScreen for URL reputation, Controlled Folder Access for ransomware, and cloud-delivered protection is a reasonable floor. The Microsoft Defender for Individuals app extends coverage to phones and Macs if you have a Microsoft 365 subscription.
Where it falls short: Defender is a strong baseline, not a strong ceiling. Independent tests still show it a step behind the top commercial suites on the very newest infostealer builds, and it has no isolated browser mode for banking sessions.
Pricing:
- Free: Included with Windows 10 and 11. Defender for Individuals bundled with Microsoft 365 Personal or Family.
- Paid: Microsoft 365 Personal starts around $99.99/year.
Platforms: Windows (with Microsoft 365, also macOS, Android, iOS).
Download: Microsoft.com
Bottom line: The right free baseline. Pair it with HitmanPro.Alert or Malwarebytes for the second layer.
How to pick the right one
- If you want the best single free option: Avast One goes further than Defender on browser data protection.
- If you’ll pay for one dedicated tool: Malwarebytes Premium for detection quality.
- If you handle banking or admin work from your daily browser: Bitdefender Total Security for Safepay’s isolated session.
- If you already trust Kaspersky and no policy forbids it: Kaspersky Plus.
- If you run Windows and want maximum raw detection: Emsisoft Anti-Malware.
- If you cover a small mixed Windows/Mac household: Sophos Home Premium.
- If you want a second layer over what you already have: HitmanPro.Alert.
- If you plan to spend zero and accept the baseline: Microsoft Defender, with Controlled Folder Access on.
FAQ
What is an infostealer and why is it different from other malware?
An infostealer is malware whose only job is to grab saved credentials, browser cookies, autofill data, crypto wallets, and messenger tokens from an infected machine and ship them to an attacker. Unlike ransomware, it does not announce itself. Because it steals live session cookies, the attacker can log into your accounts without needing to bypass MFA.
Is Microsoft Defender enough on its own?
For a low-risk casual user who doesn’t do banking, crypto, or sensitive work on the machine, Defender is a reasonable baseline. For anyone who logs into important accounts from Chrome or Edge, layering a second tool (Malwarebytes or HitmanPro.Alert) meaningfully improves your odds against new stealer builds.
Can free antivirus stop infostealers?
The free tier of Avast One and Malwarebytes free scanner both catch known stealer families. The gap between free and paid is mostly around real-time browser data protection and behavior blocking of unknown variants, which is where paid tiers earn their price.
Do I need this on my Mac?
Yes. Atomic Stealer and MacStealer specifically target macOS Keychain and browser data, and their distribution through cracked-app forums has been rising since 2024. Bitdefender, Sophos, Kaspersky, and Malwarebytes all have real macOS agents.
What about Linux?
Consumer-grade AV for Linux is thin. ClamAV, chkrootkit, and rkhunter are the standard open-source layer. Sophos and ESET sell paid Linux endpoint products aimed at servers rather than desktops.
Will an antivirus recover accounts if a stealer already got them?
No. Once the cookies are stolen, the attacker holds an authenticated session that survives even a password change. Recovery means logging out of all sessions on every affected account, rotating passwords, revoking active refresh tokens, and forcing MFA re-enrollment. Antivirus prevents the theft; it can’t undo one that already happened.
