应该是solusvm面板的0day漏洞引起。今天折腾起我在123systems上的vps，突然发现控制面板上不去了，于是发了个ticket过去，得到如下回复：
The exploit from 6/16/2013 has been patched by the software distributor, however, numerous reports are still stating that there are several other zero day exploits currently unknown to the software distributor and are still unpatched.
详见：https://www.123systems.net/policy.html