Function TestIsExpressionEvaluable

pkg/rules/sequence_test.go:1085–1131

(t *testing.T)

}

func TestIsExpressionEvaluable(t *testing.T) {
	log.SetLevel(log.DebugLevel)

	c := &config.FilterConfig{Name: "Command shell created a temp file"}
	f := filter.New(`
	sequence
	maxspan 100ms
  	|evt.name = 'CreateProcess' and ps.name = 'cmd.exe'| by ps.exe
  	|evt.name = 'CreateFile' and file.path icontains 'temp'| by file.path
	`, &config.Config{EventSource: config.EventSourceConfig{EnableFileIOEvents: true}, Filters: &config.Filters{}})
	require.NoError(t, f.Compile())

	ss := newSequenceState(f, c, new(ps.SnapshotterMock))

	e1 := &event.Event{
		Type: event.CreateProcess,
		Name: "CreateProcess",
		Tid:  2484,
		PID:  859,
		PS: &pstypes.PS{
			Name: "cmd.exe",
			Exe:  "C:\\Windows\\system32\\svchost.exe",
		},
		Params: event.Params{
			params.ProcessID: {Name: params.ProcessID, Type: params.Uint32, Value: uint32(4143)},
		},
		Metadata: map[event.MetadataKey]any{"foo": "bar", "fooz": "barzz"},
	}

	e2 := &event.Event{
		Type: event.RenameFile,
		Name: "RenameFile",
		Tid:  2484,
		PID:  859,
		PS: &pstypes.PS{
			Name: "cmd.exe",
			Exe:  "C:\\Windows\\system32\\svchost.exe",
		},
		Params: event.Params{
			params.FilePath: {Name: params.FilePath, Type: params.UnicodeString, Value: "C:\\Temp\\dropper"},
		},
		Metadata: map[event.MetadataKey]any{"foo": "bar", "fooz": "barzz"},
	}

	assert.False(t, ss.filter.GetSequence().Expressions[0].IsEvaluable(e2))
	assert.True(t, ss.filter.GetSequence().Expressions[0].IsEvaluable(e1))
}