Infection Monkey

Infection Monkey is a free, open-source breach and attack simulation tool for examining how an intruder could move through a data center or cloud environment. It suits security teams that can run a self-hosted assessment and want a view of reachable systems and possible attack paths.

Overview

The product pairs Monkey Agent, which scans systems and simulates attack techniques, with Monkey Island, a web server that coordinates agents and provides the interface. A network map shows visible machines, accessible services, and potential propagation routes; a report summarizes security issues agents discover or exploit. Together, these give teams a way to trace how access to one system might expose others.

Infection Monkey is designed to help organizations validate security controls and identify network gaps. Its FAQ says it avoids exploits or attacks that could affect target systems, including EternalBlue. That approach fits controlled resilience reviews; teams seeking destructive stress tests should choose another method.

Key features

Network mapping and reporting

The map connects reachable machines and services to possible propagation routes, which can help a team prioritize where a perimeter breach could lead. The report captures issues found or exploited by agents, giving reviewers findings to examine alongside the paths that exposed them.

Deployment and integrations

Akamai says Infection Monkey supports on-premises environments, containers, and public and private clouds. Its documented AWS integration uses Systems Manager to run the tool on EC2 instances. Internet access is optional: when available, the product checks for updates and whether machines can reach the internet. This flexibility suits mixed environments, though it still calls for a host that meets the product’s requirements.

Plugins and safeguards

Plugins can be installed, updated, removed, or uploaded through the Monkey Island interface, allowing teams to extend the tool’s functionality. The FAQ says passwords, SSH keys, and hashes are encrypted in the Island database and sent to agents over HTTPS. Users create credentials at first launch, after which those credentials are required to access the server. These protections matter because the assessment may involve sensitive access data, but teams remain responsible for securing the host and credentials they use.

Pricing

Infection Monkey is free: its Free plan costs nothing and describes an open-source breach and attack simulation tool. There is no free trial because the product is offered as a free plan. That makes it a straightforward option for organizations able to operate the software themselves; there is no paid tier in the supplied plan information for teams looking for a commercial subscription.

Platforms

The product is listed for Linux, Windows, web, and self-hosted use. The documented Monkey Island host runs on x86-64 processors, with Linux and Windows listed as supported operating systems. Teams should check that their planned host meets those requirements before adopting it. The deployment model is hybrid, and the listed attack surfaces include local networks, internal servers, on-premises data centers, and cloud-based data centers. Agent-based simulation and custom attack scenarios are also supported.

Who it's for

Infection Monkey is aimed at organizations that want to validate security controls and understand how attackers might exploit gaps across internal networks or data centers. It is a stronger fit for teams comfortable with self-hosting and operating an assessment tool than for buyers seeking a managed service. A public Slack workspace, support email, and GitHub issue reporting provide routes to project support.

Pros and cons

• Free and open source: organizations can use the core breach and attack simulation tool without a paid plan.
• Useful network-level outputs: the map links visible systems and services with potential propagation paths, and the report summarizes issues agents find or exploit.
• Broad environment coverage: support for on-premises, container, and public and private cloud environments can help teams assess varied infrastructure.
• Host requirements constrain deployment: Monkey Island requires x86-64 hardware and a supported Linux or Windows operating system.
• Self-hosting demands operational ownership: teams need to run the server and manage its credentials and any sensitive assessment data themselves.

Alternatives

Atomic Red Team is another free, cross-platform option; its open-source project emphasizes tests that run in five minutes or less with minimal setup, making it a fit for readers who want short, focused tests.

AttackIQ Platform offers free testing packages and adversary research, plus a $300, paid once pay-as-you-go plan. It may suit teams looking for those packages or a credit-based purchase option.

MITRE Caldera is a free, Apache-licensed cybersecurity framework for readers who prefer that framework approach.

OpenAEV has a free forever Community Edition with on-premise core attack simulation, tabletop exercises, and community support; consider it if tabletop exercises are part of the requirement.

FourCore ATTACK is a paid alternative for readers comparing commercial offerings.

Pentera Platform uses custom pricing, with commercial details provided through a personalized demo.

Stratus Red Team is another free option.

BlackNoise BAS is a paid alternative.

Browse more options in Breach and Attack Simulation Software.

Verdict

Choose Infection Monkey if your security team wants a free, open-source way to map potential routes through internal systems and review security control gaps across on-premises and cloud environments. Its combination of network mapping, reporting, and plugins gives the assessment useful context. Look elsewhere if you need a managed service or a commercial subscription, or if your Monkey Island host cannot meet the x86-64 and supported operating-system requirements.