我找到了这一行Invalid method in request \x16\x03\x01 on error_log file,以及其他类似的行,如:
[Wed Oct 27 23:16:37 2010] [error] [client 187.117.240.164] Invalid URI in request x\xb2\xa1:SMl\xcc{\xfd"\xd1\x91\x84!d\x0e~\xf6:\xfbVu\xdf\xc3\xdb[\xa9\xfe\xd3lpz\x92\xbf\x9f5\xa3\xbbvF\xbc\xee\x1a\xb1\xb0\xf8K\xecE\xb