So the university IT security team and I  have been going around and around on this with no breaks... anyone have any thoughts on this:I recently set up a small file server for my lab running Debian 8.6 on a dedicated computer (Intel Avoton C2550 processor -- happy to provide more hardware info if needed, but I think unnecessary). Debian installed without any problems, and at the time I also installed Samba, NTP, ZFS, and python. Things seemed to be working fine, so I let it sit and run in the corner of the lab for a few weeks.About two weeks ago, I received an email from the IT team saying there that my server has been compromised and is vulnerable being used in an NTP amplification/DDoS attack (NTP Amplification Attacks Using CVE-2013-5211 as described in https://www.us-cert.gov/ncas/alerts/TA14-013A ). The sign they pointed to was a lot of NTPv2 traffic on port 123. Weirdly, the IP address that they identified this coming from (*.*.*.233) was different from the ip address my server was configured for and reported via ifconfig (*.*.*.77). Nevertheless, some basic troubleshooting revealed that my computer was indeed generating this traffic on port 123 (as revealed by tcpdump).Here is where the bizarreness began. I first ran through the fixes recommended for CVE-2013-5211 (both updating the NTP past version 4.2.7 as well as disabling monlist functionality). Neither stemmed the traffic flow. I then tried blocking the UDP 123 port via IP tables:$ /sbin/iptables -A INPUT -o eth0 -p udp --destination-port 123 -j DROP$ /sbin/iptables -A OUTPUT -o eth0 -p udp --destination-port 123 -j DROPbut that too had no effect on the traffic. I finally tried purging NTP from the system, but that had no effect on the traffic either. As of this afternoon, nmap was still reporting:Starting Nmap 5.51 ( http://nmap.org ) at 2016-12-19 16:15 ESTNmap scan report for *.233Host is up (0.0010s latency).PORT    STATE SERVICE123/udp open  ntp| ntp-monlist:|   Public Servers (2)|       50.116.52.97    132.163.4.101|   Public Clients (39)|       54.90.159.15    185.35.62.119   185.35.62.233   185.35.63.86|       54.197.89.98    185.35.62.142   185.35.62.250   185.35.63.108|       128.197.24.176  185.35.62.144   185.35.62.251   185.35.63.128|       180.97.106.37   185.35.62.152   185.35.63.15    185.35.63.145|       185.35.62.27    185.35.62.159   185.35.63.27    185.35.63.146|       185.35.62.52    185.35.62.176   185.35.63.30    185.35.63.167|       185.35.62.65    185.35.62.186   185.35.63.34    185.35.63.180|       185.35.62.97    185.35.62.194   185.35.63.38    185.35.63.183|       185.35.62.106   185.35.62.209   185.35.63.39    185.35.63.185|_      185.35.62.117   185.35.62.212   185.35.63.43Which is all very weird since NTP has been purged from the system for weeks now.After hitting a dead end on this path, I started thinking about the whole IP-address mismatch issue. My computer seemed to be sitting on both *.233 and *.77 IPs (as confirmed by successfully pinging both with ethernet cable attached and both unavailable with cable unplugged), but *.233 never shows up in ifconfig:Link encap:Ethernet  HWaddr d0:XX:XX:51:78:XX  inet addr:*.77  Bcast:*.255  Mask:255.255.255.0inet6 addr: X::X:X:X:787a/64 Scope:LinkUP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1RX packets:23023571 errors:0 dropped:1362 overruns:0 frame:0TX packets:364849 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000 RX bytes:7441732389 (6.9 GiB)  TX bytes:44699444 (42.6 MiB)Memory:df300000-df37ffff There is no reference to *.233 in /etc/network/interfaces, so I don't see where this IP assignment is coming from.So, I have two likely related questions I'm hoping someone can help me with:1) How can I eliminate this NTP traffic from spewing from my server to get IT off my back?2) What is up with this second IP address my server is sitting on and how can I remove it?Thanks, folks :)UPDATE:As requested:$iptables -L -v -nChain INPUT (policy ACCEPT 57 packets, 6540 bytes) pkts bytes target     prot opt in     out     source               destination         Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target     prot opt in     out     source               destination         Chain OUTPUT (policy ACCEPT 27 packets, 2076 bytes) pkts bytes target     prot opt in     out     source               destinationAnd $ip addr ls1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00    inet 127.0.0.1/8 scope host lo       valid_lft forever preferred_lft forever    inet6 ::1/128 scope host        valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000    link/ether d0:50:99:51:78:7a brd ff:ff:ff:ff:ff:ff    inet *.77/24 brd *.255 scope global eth0       valid_lft forever preferred_lft forever    inet *.167/24 brd *.255 scope global secondary dynamic eth0       valid_lft 24612sec preferred_lft 24612sec    inet6 X::X:X:X:787a/64 scope link        valid_lft forever preferred_lft forever3: eth1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000    link/ether d0:50:99:51:78:7b brd ff:ff:ff:ff:ff:ffUPDATE 2:I failed to mention that in addition to the IP address not matching up, the MAC ID also did not match. This really made me think twice about whether the traffic was indeed coming from my machine. However: (1) unplugging my server from the network made the traffic disappear; (2) move to a different network port and the traffic followed; and (3) tcpdump port 123 showed the aberrant traffic:13:24:33.329514 IP cumm024-0701-dhcp-233.bu.edu.ntp > 183.61.254.77.44300: NTPv2, Reserved, length 44013:24:33.329666 IP cumm024-0701-dhcp-233.bu.edu.ntp > 183.61.254.77.44300: NTPv2, Reserved, length 44013:24:33.329777 IP cumm024-0701-dhcp-233.bu.edu.ntp > 183.61.254.77.44300: NTPv2, Reserved, length 296UPDATE 3:$ss -uapn 'sport = :123'State      Recv-Q Send-Q                  Local Address:Port                    Peer Address:Port (i.e., nothing)$sudo cat /proc/net/devInter-|   Receive                                                |  Transmit face |bytes    packets errs drop fifo frame compressed multicast|bytes    packets errs drop fifo colls carrier compressed    lo:  327357    5455    0    0    0     0          0         0   327357    5455    0    0    0     0       0          0  eth1:       0       0    0    0    0     0          0         0        0       0    0    0    0     0       0          0  eth0: 13642399917 36270491    0 6522    0     0          0   2721337 45098276  368537    0    0    0     0       0          0UPDATE 4:Those packets were typical of a few days ago. Today (but yes, still very high):20:19:37.011762 IP cumm024-0701-dhcp-233.bu.edu.ntp > 103.56.63.147.26656: NTPv2, Reserved, length 15220:19:37.011900 IP cumm024-0701-dhcp-233.bu.edu.ntp > 202.83.122.78.58066: NTPv2, Reserved, length 15220:19:37.012036 IP cumm024-0701-dhcp-233.bu.edu.ntp > 103.56.63.147.17665: NTPv2, Reserved, length 15220:19:37.014539 IP cumm024-0701-dhcp-233.bu.edu.ntp > 202.83.122.78.27945: NTPv2, Reserved, length 15220:19:37.015482 IP cumm024-0701-dhcp-233.bu.edu.ntp > 202.83.122.78.42426: NTPv2, Reserved, length 15220:19:37.015644 IP cumm024-0701-dhcp-233.bu.edu.ntp > 103.56.63.147.16086: NTPv2, Reserved, length 152$ sudo ss -uapn '( sport = :42426 or dport = :42426 )'State       Recv-Q Send-Q                                                        Local Address:Port                                                          Peer Address:Port Yes, I can ping the *.233 IP:$ping 128.197.112.233PING 128.197.112.233 (128.197.112.233) 56(84) bytes of data.64 bytes from 128.197.112.233: icmp_seq=1 ttl=64 time=0.278 ms64 bytes from 128.197.112.233: icmp_seq=2 ttl=64 time=0.282 ms64 bytes from 128.197.112.233: icmp_seq=3 ttl=64 time=0.320 msNo, the MAC don't matchMy hardware MAC address is: d0:50:99:51:78:7aThe traffic is associate with MAC: bc:5f:f4:fe:a1:00 UPDATE 5:As requested, a port scan against *.233:Starting Nmap 6.00 ( http://nmap.org ) at 2016-12-20 20:38 EETNSE: Loaded 17 scripts for scanning.Initiating SYN Stealth Scan at 20:38Scanning cumm024-0701-dhcp-233.bu.edu (128.197.112.233) [1024 ports]Discovered open port 22/tcp on 128.197.112.233Completed SYN Stealth Scan at 20:38, 9.79s elapsed (1024 total ports)Initiating Service scan at 20:38Scanning 1 service on cumm024-0701-dhcp-233.bu.edu (128.197.112.233)Completed Service scan at 20:38, 0.37s elapsed (1 service on 1 host)Initiating OS detection (try #1) against cumm024-0701-dhcp-233.bu.edu (128.197.112.233)Initiating Traceroute at 20:38Completed Traceroute at 20:38, 0.10s elapsedNSE: Script scanning 128.197.112.233.[+] Nmap scan report for cumm024-0701-dhcp-233.bu.edu (128.197.112.233)Host is up (0.083s latency).Not shown: 1013 filtered portsPORT    STATE  SERVICE VERSION21/tcp  closed ftp22/tcp  open   ssh     OpenSSH 5.5p1 Debian 6+squeeze1 (protocol 2.0)23/tcp  closed telnet25/tcp  closed smtp43/tcp  closed whois80/tcp  closed http105/tcp closed unknown113/tcp closed ident210/tcp closed z39.50443/tcp closed https554/tcp closed rtspDevice type: general purposeRunning: Linux 2.6.XOS CPE: cpe:/o:linux:kernel:2.6OS details: DD-WRT v24-sp2 (Linux 2.6.19)Uptime guess: 45.708 days (since Sat Nov  5 03:39:36 2016)Network Distance: 9 hopsTCP Sequence Prediction: Difficulty=204 (Good luck!)IP ID Sequence Generation: All zerosService Info: OS: Linux; CPE: cpe:/o:linux:kernelTRACEROUTE (using port 25/tcp)HOP RTT      ADDRESS1   0.95 ms  router1-lon.linode.com (212.111.33.229)2   0.70 ms  109.74.207.03   1.09 ms  be4464.ccr21.lon01.atlas.cogentco.com (204.68.252.85)4   1.00 ms  be2871.ccr42.lon13.atlas.cogentco.com (154.54.58.185)5   63.45 ms be2983.ccr22.bos01.atlas.cogentco.com (154.54.1.178)6   63.60 ms TrusteesOfBostonUniversity.demarc.cogentco.com (38.112.23.118)7   63.55 ms comm595-core-res01-gi2-3-cumm111-bdr-gw01-gi1-2.bu.edu (128.197.254.125)8   63.61 ms cumm024-dist-aca01-gi5-2-comm595-core-aca01-gi2-2.bu.edu (128.197.254.206)9   90.28 ms cumm024-0701-dhcp-233.bu.edu (128.197.112.233)OS and Service detection performed. Please report any incorrect results at http://nmap.org/submit/ .Nmap done: 1 IP address (1 host up) scanned in 20.73 seconds           Raw packets sent: 557 (25.462KB) | Rcvd: 97 (8.560KB)and on UDP:Starting Nmap 6.00 ( http://nmap.org ) at 2016-12-20 20:44 EETNSE: Loaded 17 scripts for scanning.Initiating Ping Scan at 20:44Scanning 128.197.112.233 [4 ports]Completed Ping Scan at 20:44, 1.10s elapsed (1 total hosts)Initiating UDP Scan at 20:44Scanning cumm024-0701-dhcp-233.bu.edu (128.197.112.233) [1024 ports]Completed UDP Scan at 20:44, 6.31s elapsed (1024 total ports)Initiating Service scan at 20:44Scanning 1024 services on cumm024-0701-dhcp-233.bu.edu (128.197.112.233)Service scan Timing: About 0.39% doneService scan Timing: About 3.12% done; ETC: 22:12 (1:25:46 remaining)Service scan Timing: About 6.05% done; ETC: 21:53 (1:04:39 remaining)Service scan Timing: About 8.98% done; ETC: 21:46 (0:56:03 remaining)Discovered open port 123/udp on 128.197.112.233Discovered open|filtered port 123/udp on cumm024-0701-dhcp-233.bu.edu (128.197.112.233) is actually openCompleted Service scan at 21:31, 2833.50s elapsed (1024 services on 1 host)Initiating OS detection (try #1) against cumm024-0701-dhcp-233.bu.edu (128.197.112.233)Retrying OS detection (try #2) against cumm024-0701-dhcp-233.bu.edu (128.197.112.233)NSE: Script scanning 128.197.112.233.Initiating NSE at 21:31Completed NSE at 21:31, 10.02s elapsed[+] Nmap scan report for cumm024-0701-dhcp-233.bu.edu (128.197.112.233)Host is up (0.089s latency).Not shown: 1023 open|filtered portsPORT    STATE SERVICE VERSION123/udp open  ntp?1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at http://www.insecure.org/cgi-bin/servicefp-submit.cgi :SF-Port123-UDP:V=6.00%I=7%D=12/20%Time=58597D5C%P=x86_64-unknown-linux-gnuSF:%r(NTPRequest,30,\xe4\x02\x04\xee\0\0\x8a\xff\0:t\xd9\x84\xa3\x04e\xdbSF:\xcaeEX\xdbC'\xc5O#Kq\xb1R\xf3\xdc\x03\xfb\xb8\+>U\xab\xdc\x03\xfb\xb8\SF:+T\xd1\xe9)%r(Citrix,C,\xde\xc0\x010\x02\0\xa8\xe3\0\0\0\0);Too many fingerprints match this host to give specific OS detailsNetwork Distance: 9 hopsOS and Service detection performed. Please report any incorrect results at http://nmap.org/submit/ .Nmap done: 1 IP address (1 host up) scanned in 2863.89 seconds           Raw packets sent: 175 (6.720KB) | Rcvd: 50 (10.088KB)
Ghost NTP server on Debian 8.6
debian;ip;network interface;tcpdump;ntp
This is a server class machine with IPMI. The ghost NTP server that is causing the issue is running on the BMC processor on the system and not the main CPU.