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ClamAV

What ClamAV is
ClamAV is a free, open-source antivirus engine for scanning email and web content and supporting endpoint security work. It includes a multi-threaded daemon, a command-line scanner, and a utility for automatic virus database updates. The database updates multiple times per day, and the updater supports scripted updates and digital signatures. The engine handles standard mail formats, many archives and executable formats, and documents including MS Office, HTML, RTF, and PDF. A Milter interface supports Sendmail. On modern Linux systems, ClamOnAcc can scan files when they are accessed, with an optional setting to block access until scanning finishes. Signed signature databases restrict the engine to trusted definitions. The project regularly tests GNU/Linux, FreeBSD, macOS, and Windows, and provides official Docker images for Alpine Linux and Debian Linux. ClamAV is an engine and set of tools, not a traditional antivirus or endpoint security suite. Recommended minimum resources are 3 GiB of RAM, a 2.0 GHz CPU, and 5 GiB of free disk space. It does not guarantee extraction of every supported format variant.
Who it suits
It suits users who need an open-source scanning engine and related tools for email, web content, or endpoint security tasks. It is not presented as a full traditional antivirus or endpoint security suite.
What it does well
- Free, open-source engine.
- Database updates multiple times per day.
- Scans common mail, archive, executable, and document formats.
- On-access scanning is available on modern Linux.
- Official Docker images are available for Alpine and Debian.
What to know first
- Not a traditional antivirus or endpoint security suite.
- Recommended minimum is 3 GiB RAM and 5 GiB disk.
- Does not guarantee extraction of every format variant.
Limits
ClamAV is an engine rather than a traditional antivirus or endpoint security suite. The project does not guarantee extraction of every version or variant of supported formats.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| ClamAV | Open-source anti-virus engine under GPL; no paid plan or price stated | Free |
| ClamAV open-source software | free of charge · GPL-2.0 software · self-hosted | Free |
As clamav.net lists them, read 7 Oct 2026. The maker's own page has the final word.
Getting started
- Visit https://www.clamav.net/ to access the project and its downloads.
- Choose a package for GNU/Linux, FreeBSD, macOS or Windows, or use an official Docker image for Alpine Linux or Debian Linux.
- Verify a release package from the downloads page with GnuPG and the Cisco Talos public key.
- Use the daemon, command-line scanner or automatic database update tool.
ClamAV is a free, open-source antivirus engine for email and web scanning and endpoint security. It best suits administrators and technically capable users building scanning into their own workflows. Its frequent signature updates and integration tools are valuable, but it is not a complete endpoint security suite.
Overview
ClamAV offers a multi-threaded daemon, a command-line scanner and a tool for automatic database updates. Together, these support both managed scanning services and scripts, rather than a turnkey security experience. Its Milter interface for Sendmail is useful for mail-server operators using that system; it is a narrower integration than a general endpoint suite.
The virus database updates multiple times per day, and the updater supports scripted updates and digital signatures. Signed databases ensure the engine executes trusted signature definitions. ClamAV scans standard mail formats and many archive, executable and document formats, including MS Office, HTML, RTF and PDF. But it does not guarantee extraction of every supported format version or variant, so format support is broad rather than exhaustive.
Key features
Scanning and Linux on-access protection
The command-line scanner suits direct or scripted scanning, while the multi-threaded daemon supports scanning workloads that benefit from parallel processing. On modern Linux versions, ClamOnAcc can scan files as they are accessed and optionally block access until scanning finishes. That option can make scanning more immediate, but its Linux scope does not make ClamAV a cross-platform endpoint suite.
Updates and deployment
Automatic, scriptable updates and signed definitions make ClamAV a fit for environments that manage their own scanning and update routines. Release packages can be verified with GnuPG and the Cisco Talos public key, and official Docker images are available for Alpine Linux and Debian Linux. These options favor operators comfortable with verification and deployment choices.
Pricing
ClamAV is free: its ClamAV plan costs nothing and is an open-source antivirus engine under GPL. There is no paid plan or free trial. That makes it a straightforward choice when a scanning engine is needed without a software charge, but the free engine should not be mistaken for a bundled endpoint-security package.
Platforms
ClamAV supports GNU/Linux, FreeBSD, macOS and Windows, and those are the project’s regularly tested operating systems. ClamOnAcc’s on-access scanning applies to modern Linux versions, so users on other systems should not assume they get that particular capability. The recommended minimum is 3 GiB of RAM, a 2.0 GHz CPU and 5 GiB of free disk space; those requirements matter for lean systems and constrained deployments.
Who it's for
ClamAV is best for administrators, mail-server operators and technically capable users who want an open-source engine for scanning and can integrate it into a broader setup. Its daemon, command-line scanner, update tool and Docker images give deployment flexibility. Users seeking a traditional endpoint suite should look elsewhere, as should anyone who needs guaranteed extraction across every supported file variant.
Pros and cons
- Pro: Multiple daily database updates and signed definitions support current, trusted signature use.
- Pro: The daemon, command-line scanner, scripted updater and Sendmail Milter interface suit varied managed workflows.
- Pro: Support for several operating systems and common mail, archive, executable and document formats gives it broad scanning reach.
- Con: ClamAV is an engine, not a traditional antivirus or endpoint security suite, so it is not a complete security package.
- Con: Format extraction is not guaranteed for every version or variant, which can leave gaps in specific workflows.
- Con: The recommended 3 GiB RAM, 2.0 GHz CPU and 5 GiB free disk requirements may be substantial for constrained systems.
Alternatives
For a browser-oriented option, AVG Secure Browser has a free plan with ad blocking, anti-tracking, private browsing and web protection for Windows, macOS and Android. ESET Mobile Security for Android is the more relevant choice for Android devices: it offers a free lifetime subscription with basic features and a premium tier for Android phones or tablets.
Readers looking for a paid, multi-device suite can consider Bitdefender Total Security, whose first-year individual plan is $59.99 a year plus applicable sales tax for five devices under one account. For managed endpoint protection across desktop and mobile systems, Kaspersky Endpoint Security for Business offers a Select plan with endpoint protection for Windows, Linux, Mac, Android and iOS, with EDR as an add-on.
Seqrite Endpoint Protection Cloud is another paid endpoint option, with Standard and Advanced plans. Heimdal Security offers paid home plans, including Next-Gen Antivirus Home at $59.95 a year and Threat Prevention Home at $69.95 a year, each billed yearly for one year and three PCs. For endpoint protection with device control, application blocking and vulnerability assessment, ThreatDown Endpoint Protection offers its Core Next-Gen AV plan. Trellix Data Loss Prevention is the alternative for enterprise data loss prevention across endpoints, email, web, networks and storage, with on-premises or SaaS management.
Browse Business Antivirus Software, Malware Removal Software, Antivirus for Mac and Antivirus software for more options.
Verdict
Choose ClamAV if you want a free, open-source scanning engine with frequent signature updates and tools that fit managed or scripted deployments. Its main advantage is flexibility across scanning workflows; its main limitation is equally clear: it is not a full endpoint suite, and its extraction coverage is not guaranteed for every format variant. For turnkey endpoint protection, choose a suite instead.
Verdict
ClamAV provides scanning tools, frequent database updates, and coverage across several operating systems and file formats. Readers should account for its engine-focused scope, resource recommendations, and format-extraction caveat.
Questions
Does ClamAV cost anything?
ClamAV is free and open source under the GPL. The listed plan is $0.00 per free, and no paid plan or price is stated.
Which operating systems does ClamAV support?
The project lists GNU/Linux, FreeBSD, macOS and Windows among its regularly tested platforms.
Does it scan files as they are accessed?
ClamOnAcc provides on-access scanning on modern Linux versions, with an option to block access until scanning completes.
What formats can it scan?
It supports standard mail formats, many archive and executable formats, and document formats including MS Office, HTML, RTF and PDF. The project does not guarantee extraction of every version or variant.
Is ClamAV a complete endpoint security suite?
No. ClamAV is an antivirus engine and set of tools, rather than a traditional antivirus or endpoint security suite.
What system resources does the project recommend?
The recommended minimum is 3 GiB of RAM, a 2.0 GHz CPU and 5 GiB of free disk space.
Facts from ClamAV's own pages
- API and library
- The core engine is available as a shared library, and applications can use clamd through its socket protocol. · docs.clamav.net, 15 Oct 2026
- Archive support
- Built-in extraction covers formats including ZIP, RAR, 7-Zip, ARJ, TAR, gzip, bzip2, DMG, ISO, OLE2, OOXML, Cabinet and CHM. · docs.clamav.net, 15 Oct 2026
- Automatic updates
- FreshClam periodically downloads new virus databases and verifies signed updates. · docs.clamav.net, 15 Oct 2026
- Bytecode engine
- Its bytecode runtime lets signature authors distribute complex detection routines that execute inside the scanner. · docs.clamav.net, 15 Oct 2026
- Command-line scanner
- ClamAV includes the clamscan command-line utility for on-demand file scanning. · clamav.net, 15 Oct 2026
- Company founded
- LinkedIn lists Cisco as founded in 1984. · linkedin.com, 15 Oct 2026
- Company funding record
- Crunchbase lists Sequoia Capital as a Cisco investor and shows one funding round, while concealing the amount. · crunchbase.com, 15 Oct 2026
- Company headquarters
- Cisco is headquartered in San Jose, California, United States. · linkedin.com, 15 Oct 2026
- Company legal name
- Crunchbase lists the maker's legal name as Cisco Systems, Inc. · crunchbase.com, 15 Oct 2026
- Company size
- LinkedIn lists Cisco's company size as 10,001 or more employees. · linkedin.com, 15 Oct 2026
- Current release
- The stable release listed in 2026 is version 1.5.4, released on 7 August 2026. · en.wikipedia.org, 15 Oct 2026
- Database cadence
- The official virus database is normally updated once or twice daily. · docs.clamav.net, 15 Oct 2026
- Deployment options
- Official Docker images are available for Alpine Linux and Debian Linux. · docs.clamav.net, 7 Oct 2026
- Documentation depth
- The documentation includes usage diagrams, installation procedures, configuration guidance, signature writing, FAQs and on-access recipes. · docs.clamav.net, 15 Oct 2026
- Document support
- The engine parses formats such as Microsoft Office, HTML, RTF, PDF, OneNote and HWP. · docs.clamav.net, 15 Oct 2026
- Download verification
- ClamAV release packages from its downloads page can be verified using GnuPG and the Cisco Talos public key. · docs.clamav.net, 7 Oct 2026
- Executable support
- ClamAV parses 32-bit and 64-bit PE files plus ELF and Mach-O binaries, including several packed formats. · docs.clamav.net, 15 Oct 2026
- Extensibility
- Administrators can add custom signature files and use supported YARA rules alongside the standard databases. · freebsdsoftware.org, 15 Oct 2026
- File coverage
- It supports standard mail formats, many archive formats, executable formats, and popular document formats including MS Office, HTML, RTF, and PDF. · clamav.net, 7 Oct 2026
- Format limitation
- The project does not guarantee it can unpack or extract every version or variant of supported formats. · docs.clamav.net, 7 Oct 2026
- Free plan
- Yes · clamav.net, 20 Sept 2026
- Installation choices
- Official instructions cover package managers, Linux DEB/RPM packages, macOS PKG, Windows installer or portable ZIP, Docker images and source builds. · docs.clamav.net, 15 Oct 2026
- License
- ClamAV is licensed under the GNU General Public License version 2. · docs.clamav.net, 15 Oct 2026
- Limit: detection coverage
- Independent testing summarized by Wikipedia reported 59.94% overall detection in a 2022 commodity-malware study, with weaker results for several file types and malware categories. · en.wikipedia.org, 15 Oct 2026
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