MacOS Keyboard Events

from fnmatch import fnmatch

# sip protects against writing malware into the paths below.
# additional apps can be added to this list based on your environments.
#
# more info: https://support.apple.com/en-us/HT204899
APPROVED_PROCESS_PATHS = {
    "/System/*",
    "/usr/*",
    "/bin/*",
    "/sbin/*",
    "/var/*",
}

APPROVED_APPLICATION_NAMES = {"Adobe Photoshop CC 2019"}


def rule(event):
    if "Keyboard_Event_Taps" not in event.get("name", ""):
        return False

    if event.get("action") != "added":
        return False

    process_path = event.deep_get("columns", "path", default="")
    if process_path == "":
        return False

    if event.deep_get("columns", "name") in APPROVED_APPLICATION_NAMES:
        return False

    # Alert if the process is running outside any of the approved paths
    # TODO: Convert this fnmatch pattern below to a helper
    return not any((fnmatch(process_path, p) for p in APPROVED_PROCESS_PATHS))


def title(event):
    return f"Keylogger malware detected on [{event.get('hostIdentifier')}]"