{"id":"MAL-2026-11107","summary":"Malicious code in num-format-helper (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (04a0ecb436de3a0e93a577a3ba1733b227bd536e02acf371df530c6a320e1001)\nPackage advertises itself as a number/locale formatting helper but its postinstall.js runs automatically on npm install and shells out via child_process/exec to collect host identity (hostname, user, id, sudo, uname), GitHub Actions variables including GITHUB_TOKEN and GITHUB_REPOSITORY, a broad env dump filtered by a credential regex (KEY|TOKEN|SECRET|CREDENTIAL|KUBE|JENKINS|NPM|GEM|CARGO|AZURE|GCP|AWS_|GH_TOKEN|GITHUB_TOKEN), network interfaces, running processes, and cloud instance metadata (AWS 169.254.169.254, Aliyun 100.100.100.200, Tencent). The collected data is base64-encoded and sent via curl in a GET request to the hardcoded Burp Collaborator subdomain pzs5w7ntzhsnepwk564lyfdci3oucl0a.oastify.com. The shipped index.js is a trivial unrelated stub, confirming the package is a cover story for the install-time exfiltration payload.\n\n## Source: ossf-package-analysis (8a8aaefbf5f2df138b5dd99eeb8aa0247ffe7570759470e6ad7479fc0700345f)\nThe OpenSSF Package Analysis project identified 'num-format-helper' @ 1.0.0 (npm) as malicious.\n\nIt is considered malicious because:\n\n- The package communicates with a domain associated with malicious activity.\n\n- The package executes one or more commands associated with malicious behavior.\n","modified":"2026-08-04T22:05:11.003045418Z","published":"2026-07-28T07:15:58Z","database_specific":{"malicious-packages-origins":[{"versions":["1.0.0"],"import_time":"2026-07-28T07:26:58.386048285Z","modified_time":"2026-07-28T07:15:58Z","sha256":"8a8aaefbf5f2df138b5dd99eeb8aa0247ffe7570759470e6ad7479fc0700345f","source":"ossf-package-analysis"},{"modified_time":"2026-08-04T21:27:30Z","sha256":"04a0ecb436de3a0e93a577a3ba1733b227bd536e02acf371df530c6a320e1001","source":"amazon-inspector","versions":["1.0.0"],"id":"IN-MAL-2026-011065","import_time":"2026-08-04T21:33:15.649367338Z"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/num-format-helper/v/1.0.0"}],"affected":[{"package":{"name":"num-format-helper","ecosystem":"npm","purl":"pkg:npm/num-format-helper"},"versions":["1.0.0"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/num-format-helper/MAL-2026-11107.json","indicators":{"evidence_files":[{"path":"postinstall.js","sha256":"2f12974f8ceb206a773b9456efee5274e5bc739dc9d7436fdc7f0893ce61af82","tlsh":"834189e8f619b834364dc4f8b68e55027893e9af89f4ff74553b4db0044c98820aab36"},{"path":"package.json","sha256":"0c179333614beca723adf5554d2a96f1b8583bfe7755a204a98b1a06f3e9eddd","tlsh":"8fe0c234e92596337dc497a90d9386063a310e4b12843d0926d71458938f6b694ffb1a"}],"package_integrity":[{"hashes":{"sha1":"6866c13725327adb911d63fdd8f4339af40c5258","sha512_sri":"sha512-bH45pBvfoz4awNCW7xNhMlCEoxBsfSRMAlw+HAUTcSvf5Be9cbb+0Ph0q+QRpbUf6+fJEN4kee64J9Xlf1R5Tg=="},"filename":"num-format-helper-1.0.0.tgz"}]}}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"},{"name":"OpenSSF: Package Analysis","contact":["https://github.com/ossf/package-analysis","https://openssf.slack.com/channels/package_analysis"],"type":"FINDER"}]}