{"success":true,"data":{"ext":"msf","name":"Thunderbird|Mozilla Mail Summary File","description":"The MSF (Mozilla Mail Summary File) is an index file used by Mozilla Thunderbird and earlier Mozilla Mail applications, maintained as part of the Mozilla mail storage system. It stores summary information for mail folders, including message headers, status flags, and folder metadata, allowing the client to load and navigate mailboxes more quickly. The format is a legacy support file and can usually be recreated if deleted; it does not normally contain active content, so risk is low.","mime":[],"risk_level":"Safe","signatures":[{"hex":"2F 2F 20 3C 21 2D 2D 20 3C 6D 64 62 3A 6D 6F 72 6B 3A 7A","offset":0,"sources":[{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]}],"related":["dbx","dci","eml","emlx","mbox","msg"],"usage":{"python":"def is_msf(file_path: str) -> bool:\n    \"\"\"Check if file is a valid MSF by magic bytes.\"\"\"\n    signature = bytes([0x2F, 0x2F, 0x20, 0x3C, 0x21, 0x2D, 0x2D, 0x20, 0x3C, 0x6D, 0x64, 0x62, 0x3A, 0x6D, 0x6F, 0x72, 0x6B, 0x3A, 0x7A])\n    with open(file_path, \"rb\") as f:\n        return f.read(19) == signature","node":"function isMSF(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x2F, 0x2F, 0x20, 0x3C, 0x21, 0x2D, 0x2D, 0x20, 0x3C, 0x6D, 0x64, 0x62, 0x3A, 0x6D, 0x6F, 0x72, 0x6B, 0x3A, 0x7A]);\n  return buffer.subarray(0, 19).equals(signature);\n}","go":"func IsMSF(data []byte) bool {\n    signature := []byte{0x2F, 0x2F, 0x20, 0x3C, 0x21, 0x2D, 0x2D, 0x20, 0x3C, 0x6D, 0x64, 0x62, 0x3A, 0x6D, 0x6F, 0x72, 0x6B, 0x3A, 0x7A}\n    if len(data) < 19 {\n        return false\n    }\n    return bytes.Equal(data[:19], signature)\n}"},"category":"Email & PIM"}}