malware

Malware: ClamAV scan/update, YARA rules, suspicious files, webshells, quarantine

SERVERDefense SOURCEdefense-mcp-server

High RISK CLASS

Category Execute

Parameters 121 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/defense/malware.md

WHAT IT DOES

What malware does on Defense

AI agents invoke malware to trigger actions in Defense. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

Parameter	Type	Required	Description
`days`	number	—	Days for recently_modified check
`path`	string	—	File or directory path to scan
`action`	string	Yes	Malware detection action
`dry_run`	boolean	—	Preview without executing
`file_id`	string	—	Filename in quarantine directory
`max_depth`	number	—	Max directory depth
`recursive`	boolean	—	Recursively scan directories
`check_type`	string	—	Type of suspicious file check
`rules_path`	string	—	Path to YARA rules file (.yar/.yara)
`search_path`	string	—	Root path to search
`target_path`	string	—	File or directory to scan with YARA
`max_filesize`	string	—	Maximum file size to scan

Parameters from the server's own tool schema.

RISK

Why malware is rated High

This tool performs active operations including scanning filesystems, updating AV definitions, applying YARA rules to detect malware, and quarantining files. Quarantine moves/isolates files (potentially irreversible in effect), and scanning/executing detection rules against the live system constitutes external operation execution.

From the tool's definition ClamAV scan/update, YARA rules, suspicious files, webshells, quarantine

Risk signalsAccepts file system path (path) · High parameter count (15 properties)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs malware safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Defense, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For malware, this is the rule to start with:

malware Rate-limited

malware stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "malware": {
      "limits": [
        {
          "counter": "malware_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Defense, apply this rule, and every malware call is checked against it from then on.

FAQ

Questions about malware

What does the malware tool do? +

Malware: ClamAV scan/update, YARA rules, suspicious files, webshells, quarantine. It is categorised as a Execute tool in the Defense MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does malware accept? +

malware accepts 12 parameters: days, path, action, dry_run, file_id, max_depth, recursive, check_type, rules_path, search_path, target_path, max_filesize. Required: action. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on malware? +

Register the Defense MCP server in PolicyLayer and add a rule for malware: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Defense. Nothing to install.

What risk level is malware? +

malware is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit malware? +

Yes. Add a rate_limit block to the malware rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block malware completely? +

Set action: deny in the PolicyLayer policy for malware. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides malware? +

malware is provided by the Defense MCP server (defense-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Defense, and thousands of servers like it.

This server

All 31 Defense tools → High-risk tools on this server →

Across the catalogue

All high-risk MCP tools → The MCP Attack Database →

Guides

Govern code and CI agents →Agent sandbox →Least privilege for MCP →