Merge branch 'main' into fix/dumpsys-battery-daily-order

* intrusion_logs: alert on certificate events and run heuristics without IOCs

SecurityEvent.check_indicators() returned early when no indicator set was
loaded, so none of its heuristic alerts (key integrity, wipe failure, crypto
self-test, certificate events) reached the alert store on a default run. On
top of that, cert_authority_installed and cert_validation_failure only emitted
log.warning and never alerted even when indicators were present.

Run the heuristic alerts independently of the loaded indicators (matching the
accessibility fix in #807) and surface the two certificate events through the
alert store at medium severity. A successfully installed root CA and a
certificate validation failure are interception/MITM-relevant signals that
belong in the alert report.

Adds regression tests for both certificate events and for heuristics firing
with no indicators loaded.

* intrusion_logs: gate certificate authority install alert on success

Failed install attempts log a warning instead of raising the
"Certificate authority installed" alert. Add a regression test
covering success encoded as bool and as int.

---------

Co-authored-by: John Kavanagh <668351+kavanista@users.noreply.github.com>
Co-authored-by: besendorf <janik@besendorf.org>

.github/workflows/mypy.yml

@@ -1,5 +1,8 @@
 name: Mypy
-on: workflow_dispatch
+on:
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
 
 jobs:
   mypy_py3:

src/mvt/android/artifacts/dumpsys_battery_daily.py

@@ -50,13 +50,11 @@ class DumpsysBatteryDailyArtifact(AndroidArtifact):
     def parse(self, output: str) -> None:
         daily = None
         daily_updates: list[dict[str, Any]] = []
-        package_versions: dict[
-            str, str
-        ] = {}  # Track package versions to detect downgrades
+        records: list[dict[str, Any]] = []
         for line in output.splitlines():
             if line.startswith("  Daily from "):
                 if len(daily_updates) > 0:
-                    self.results.extend(daily_updates)
+                    records.extend(daily_updates)
                     daily_updates = []
 
                 timeframe = line[13:].strip()
@@ -89,35 +87,53 @@ class DumpsysBatteryDailyArtifact(AndroidArtifact):
                     "vers": vers_nr,
                 }
 
-                # Check for uninstall (version 0)
-                if vers_nr == "0":
-                    self.alertstore.medium(
-                        f"Detected uninstall of package {package_name} (vers 0)",
-                        daily["from"],
-                        update_record,
-                    )
-                # Check for downgrade
-                elif package_name in package_versions:
-                    try:
-                        current_vers = int(vers_nr)
-                        previous_vers = int(package_versions[package_name])
-                        if current_vers < previous_vers:
-                            update_record["action"] = "downgrade"
-                            update_record["previous_vers"] = str(previous_vers)
-                            self.alertstore.medium(
-                                f"Detected downgrade of package {package_name} "
-                                f"from vers {previous_vers} to vers {current_vers}",
-                                daily["from"],
-                                update_record,
-                            )
-                    except ValueError:
-                        # If version numbers aren't integers, skip comparison
-                        pass
-
-                # Update tracking dictionary
-                package_versions[package_name] = vers_nr
-
                 daily_updates.append(update_record)
 
         if len(daily_updates) > 0:
-            self.results.extend(daily_updates)
+            records.extend(daily_updates)
+
+        self._detect_uninstalls_and_downgrades(records)
+        self.results.extend(records)
+
+    def _detect_uninstalls_and_downgrades(
+        self, records: list[dict[str, Any]]
+    ) -> None:
+        package_versions: dict[str, int] = {}
+
+        for record in sorted(
+            records,
+            key=lambda record: (
+                record["from"],
+                record["to"],
+                record["package_name"],
+            ),
+        ):
+            package_name = record["package_name"]
+            vers_nr = record["vers"]
+
+            if vers_nr == "0":
+                self.alertstore.medium(
+                    f"Detected uninstall of package {package_name} (vers 0)",
+                    record["from"],
+                    record,
+                )
+                package_versions.pop(package_name, None)
+                continue
+
+            try:
+                current_vers = int(vers_nr)
+            except ValueError:
+                continue
+
+            previous_vers = package_versions.get(package_name)
+            if previous_vers is not None and current_vers < previous_vers:
+                record["action"] = "downgrade"
+                record["previous_vers"] = str(previous_vers)
+                self.alertstore.medium(
+                    f"Detected downgrade of package {package_name} "
+                    f"from vers {previous_vers} to vers {current_vers}",
+                    record["from"],
+                    record,
+                )
+
+            package_versions[package_name] = current_vers

src/mvt/android/modules/intrusion_logs/security_event.py

@@ -303,10 +303,15 @@ class SecurityEvent(IntrusionLogsModule):
 
     def check_indicators(self) -> None:
         """Check security events against indicators of compromise."""
-        if not self.indicators:
-            return
-
         for result in self.results:
+            # Heuristic alerts are intrinsic to the event, so they run even
+            # when no indicator set is loaded.
+            self._check_security_heuristics(result)
+
+            # The remaining checks match events against loaded indicators.
+            if not self.indicators:
+                continue
+
             # Check app process start events for suspicious package names
             if "app_process_start" in result:
                 process_info = result["app_process_start"]
@@ -390,60 +395,73 @@ class SecurityEvent(IntrusionLogsModule):
                                 matched_indicator=ioc.ioc,
                             )
 
-            # Flag failed cryptographic operations as potentially suspicious
-            if "key_generated" in result:
-                if not result["key_generated"].get("success", True):
-                    self.log.warning(
-                        "Failed key generation detected for key_id: %s",
-                        result["key_generated"].get("key_id", "unknown"),
-                    )
-
-            # Flag certificate validation failures
-            if "cert_validation_failure" in result:
+    def _check_security_heuristics(self, result: dict) -> None:
+        """Raise alerts for events that are intrinsically suspicious,
+        independent of any loaded indicators."""
+        # Flag failed cryptographic operations as potentially suspicious
+        if "key_generated" in result:
+            if not result["key_generated"].get("success", True):
                 self.log.warning(
-                    "Certificate validation failure detected: %s",
-                    result.get("cert_validation_failure"),
+                    "Failed key generation detected for key_id: %s",
+                    result["key_generated"].get("key_id", "unknown"),
                 )
 
-            # Flag key integrity violations
-            if "key_integrity_violation" in result:
+        # Flag certificate validation failures
+        if "cert_validation_failure" in result:
+            self.alertstore.medium(
+                "Certificate validation failure detected: "
+                f"{result.get('cert_validation_failure')}",
+                result.get("timestamp") or "",
+                result,
+            )
+
+        # Flag key integrity violations
+        if "key_integrity_violation" in result:
+            self.alertstore.medium(
+                f"Key integrity violation detected: {result.get('key_integrity_violation')}",
+                result.get("timestamp") or "",
+                result,
+            )
+
+        # Flag successful certificate authority installations (potential
+        # MITM); a missing success field is treated as installed
+        if "cert_authority_installed" in result:
+            cert_info = result["cert_authority_installed"]
+            if cert_info.get("success", True):
                 self.alertstore.medium(
-                    f"Key integrity violation detected: {result.get('key_integrity_violation')}",
+                    "Certificate authority installed: "
+                    f"{cert_info.get('subject', 'unknown')}",
                     result.get("timestamp") or "",
                     result,
                 )
-
-            # Flag certificate authority installations (potential MITM)
-            if "cert_authority_installed" in result:
-                cert_info = result["cert_authority_installed"]
+            else:
                 self.log.warning(
-                    "Certificate authority installed: %s (success: %s)",
+                    "Failed certificate authority install attempt: %s",
                     cert_info.get("subject", "unknown"),
-                    cert_info.get("success", "unknown"),
                 )
 
-            # Flag wipe failures
-            if "wipe_failure" in result:
+        # Flag wipe failures
+        if "wipe_failure" in result:
+            self.alertstore.medium(
+                "Device wipe failure detected",
+                result.get("timestamp") or "",
+                result,
+            )
+
+        # Flag crypto self test failures
+        if "crypto_self_test_completed" in result:
+            test_result = result["crypto_self_test_completed"]
+            if isinstance(test_result, dict):
+                success = test_result.get("success", True)
+            else:
+                success = test_result == 1
+            if not success:
                 self.alertstore.medium(
-                    "Device wipe failure detected",
+                    "Cryptographic self test failed",
                     result.get("timestamp") or "",
                     result,
                 )
 
-            # Flag crypto self test failures
-            if "crypto_self_test_completed" in result:
-                test_result = result["crypto_self_test_completed"]
-                if isinstance(test_result, dict):
-                    success = test_result.get("success", True)
-                else:
-                    success = test_result == 1
-                if not success:
-                    self.alertstore.medium(
-                        "Cryptographic self test failed",
-                        result.get("timestamp") or "",
-                        result,
-                    )
-
     def serialize(self, record: dict) -> Union[dict, list]:
         """Serialize a security event record for timeline output."""
         # Determine the event sub-type

tests/android/test_artifact_dumpsys_battery_daily.py

@@ -69,3 +69,65 @@ class TestDumpsysBatteryDailyArtifact:
         assert downgrade_alert.event["package_name"] == "com.example.app"
         assert downgrade_alert.event["action"] == "downgrade"
         assert downgrade_alert.event["previous_vers"] == "10"
+
+    def test_newest_first_update_is_not_reported_as_downgrade(self):
+        dba = DumpsysBatteryDailyArtifact()
+        dba.parse(
+            """
+  Daily from 2026-01-10 to 2026-01-11:
+      Update com.example.app vers=102
+  Daily from 2026-01-05 to 2026-01-06:
+      Update com.example.app vers=101
+"""
+        )
+
+        assert len(dba.results) == 2
+        assert len(dba.alertstore.alerts) == 0
+        assert all(result["action"] == "update" for result in dba.results)
+
+    def test_newest_first_downgrade_creates_medium_alert(self):
+        dba = DumpsysBatteryDailyArtifact()
+        dba.parse(
+            """
+  Daily from 2026-01-10 to 2026-01-11:
+      Update com.example.app vers=101
+  Daily from 2026-01-05 to 2026-01-06:
+      Update com.example.app vers=102
+"""
+        )
+
+        assert len(dba.results) == 2
+        assert len(dba.alertstore.alerts) == 1
+
+        downgrade_alert = dba.alertstore.alerts[0]
+        assert downgrade_alert.level == AlertLevel.MEDIUM
+        assert downgrade_alert.message == (
+            "Detected downgrade of package com.example.app from vers 102 to vers 101"
+        )
+        assert downgrade_alert.event_time == "2026-01-10"
+        assert downgrade_alert.event["package_name"] == "com.example.app"
+        assert downgrade_alert.event["action"] == "downgrade"
+        assert downgrade_alert.event["previous_vers"] == "102"
+
+    def test_reinstall_after_uninstall_is_not_reported_as_downgrade(self):
+        dba = DumpsysBatteryDailyArtifact()
+        dba.parse(
+            """
+  Daily from 2026-01-15 to 2026-01-16:
+      Update com.example.app vers=10
+  Daily from 2026-01-10 to 2026-01-11:
+      Update com.example.app vers=0
+  Daily from 2026-01-05 to 2026-01-06:
+      Update com.example.app vers=102
+"""
+        )
+
+        assert len(dba.results) == 3
+        assert len(dba.alertstore.alerts) == 1
+
+        uninstall_alert = dba.alertstore.alerts[0]
+        assert uninstall_alert.level == AlertLevel.MEDIUM
+        assert uninstall_alert.message == (
+            "Detected uninstall of package com.example.app (vers 0)"
+        )
+        assert uninstall_alert.event_time == "2026-01-10"

tests/android/test_intrusion_logs.py

@@ -6,12 +6,14 @@
 import json
 import logging
 
+import pytest
 from click.testing import CliRunner
 
 from mvt.android.cli import check_intrusion_logs
 from mvt.android.cmd_check_intrusion_logs import CmdAndroidCheckIntrusionLogs
 from mvt.android.modules.intrusion_logs.base import IntrusionLogsModule
 from mvt.android.modules.intrusion_logs.security_event import SecurityEvent
+from mvt.common.alerts import AlertLevel
 
 
 def _write_ndjson(path, records):
@@ -204,3 +206,82 @@ def test_check_intrusion_logs_cli_lists_modules(tmp_path):
     assert "DnsEvent" in result.output
     assert "ConnectEvent" in result.output
     assert "SecurityEvent" in result.output
+
+
+def _run_security_heuristics(results):
+    # No indicators loaded: heuristic alerts must still fire.
+    module = SecurityEvent(results=results)
+    module.check_indicators()
+    return module.alertstore.alerts
+
+
+def test_cert_authority_installed_raises_medium_alert_without_indicators():
+    alerts = _run_security_heuristics(
+        [
+            {
+                "timestamp": "2024-01-01 00:00:00.000",
+                "cert_authority_installed": {
+                    "subject": "CN=Unexpected Root CA",
+                    "success": True,
+                },
+            }
+        ]
+    )
+
+    assert len(alerts) == 1
+    assert alerts[0].level == AlertLevel.MEDIUM
+    assert "Certificate authority installed" in alerts[0].message
+    assert "Unexpected Root CA" in alerts[0].message
+
+
+# Exported logs encode success as a JSON bool, raw SecurityLog as int 0/1.
+@pytest.mark.parametrize("success", [False, 0])
+def test_failed_cert_authority_install_does_not_alert(success, caplog):
+    with caplog.at_level(logging.WARNING):
+        alerts = _run_security_heuristics(
+            [
+                {
+                    "timestamp": "2024-01-01 00:00:00.000",
+                    "cert_authority_installed": {
+                        "subject": "CN=Unexpected Root CA",
+                        "success": success,
+                    },
+                }
+            ]
+        )
+
+    assert alerts == []
+    assert "Failed certificate authority install attempt" in caplog.text
+    assert "Unexpected Root CA" in caplog.text
+
+
+def test_cert_validation_failure_raises_medium_alert_without_indicators():
+    alerts = _run_security_heuristics(
+        [
+            {
+                "timestamp": "2024-01-01 00:00:00.000",
+                "cert_validation_failure": "chain validation failed",
+            }
+        ]
+    )
+
+    assert len(alerts) == 1
+    assert alerts[0].level == AlertLevel.MEDIUM
+    assert "Certificate validation failure" in alerts[0].message
+
+
+def test_security_heuristics_fire_when_no_indicators_loaded():
+    # check_indicators() previously returned early with no indicators loaded,
+    # so none of the heuristic alerts fired on a default run.
+    alerts = _run_security_heuristics(
+        [
+            {"timestamp": "2024-01-01 00:00:00.000", "wipe_failure": {"reason": "x"}},
+            {
+                "timestamp": "2024-01-01 00:00:00.000",
+                "key_integrity_violation": {"key_id": "k1"},
+            },
+        ]
+    )
+
+    assert len(alerts) == 2
+    assert all(alert.level == AlertLevel.MEDIUM for alert in alerts)