mal-2026-3650
Vulnerability from ossf_malicious_packages
Published
2026-05-13 00:00
Modified
2026-05-13 00:00
Summary
Malicious code in microsoft-applicationinsights-common (npm)
Details

Two malicious npm packages published by the micresoft account (typosquatting "microsoft") are part of a coordinated supply chain attack sharing identical infrastructure with packages published by the superbase account. Each package bundles a 4.5 MB statically-linked, UPX-packed ELF binary at .claude/settings and a companion .claude/settings.json that registers the binary as a Claude Code SessionStart hook, causing it to execute every time Claude Code opens the compromised project directory. On initial install, the same binary is executed via a preinstall lifecycle hook. The binary connects to a C2 server at 207.90.194.2:443 and harvests environment variables, $HOME directory contents, and /proc/ filesystem entries to exfiltrate developer credentials and system state.

microsoft-applicationinsights-common impersonates @microsoft/applicationinsights-common, the official Microsoft Application Insights Common JavaScript Library. The package copies the legitimate library's full distribution including compiled browser bundles, TypeScript declarations, and metadata, then injects a preinstall hook that executes the malicious .claude/settings binary on install.

Credits
SafeDep safedep.io

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "microsoft-applicationinsights-common"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "SEMVER"
        }
      ]
    }
  ],
  "credits": [
    {
      "contact": [
        "https://safedep.io"
      ],
      "name": "SafeDep",
      "type": "FINDER"
    }
  ],
  "database_specific": {
    "malicious-packages-origins": null
  },
  "details": "Two malicious npm packages published by the `micresoft` account (typosquatting \"microsoft\") are part of a coordinated supply chain attack sharing identical infrastructure with packages published by the `superbase` account. Each package bundles a 4.5 MB statically-linked, UPX-packed ELF binary at `.claude/settings` and a companion `.claude/settings.json` that registers the binary as a Claude Code `SessionStart` hook, causing it to execute every time Claude Code opens the compromised project directory. On initial install, the same binary is executed via a `preinstall` lifecycle hook. The binary connects to a C2 server at `207.90.194.2:443` and harvests environment variables, `$HOME` directory contents, and `/proc/` filesystem entries to exfiltrate developer credentials and system state.\n\n`microsoft-applicationinsights-common` impersonates `@microsoft/applicationinsights-common`, the official Microsoft Application Insights Common JavaScript Library. The package copies the legitimate library\u0027s full distribution including compiled browser bundles, TypeScript declarations, and metadata, then injects a `preinstall` hook that executes the malicious `.claude/settings` binary on install.",
  "id": "MAL-2026-3650",
  "modified": "2026-05-13T00:00:00Z",
  "published": "2026-05-13T00:00:00Z",
  "schema_version": "1.7.4",
  "summary": "Malicious code in microsoft-applicationinsights-common (npm)"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…