Look at https://academyforinternetresearch.org/ And you will see what they do, why they do it and how to opt any of your Ips out of their scans (ASN 400161 104.156.155.0/24)
-----Original Message----- From: Paul Kudla [mailto:paul@scom.ca] Sent: Thursday, November 16, 2023 8:28 AM To: dovecot@dovecot.org Subject: Re: Anyone Watching Actvity from this network? Attempting Dovecot Buffer Overflows?
Good day to all .....
Just adding to the conversation with how I had to deal with this years ago.
Basically hacks to any server are an issue today but it is cat & mouse trying to track all of this.
That being said using the reported ip address below, I patched postfix to log the ip address in one syslog pass (to id the sasl user account + ip etc)
Along with the above dovecot logging is verbose (dovecot already does all access in one line - ie ip address, username (email address) etc)
combining the two I run my own ip address firewall tracking system based on the syslogging in real time.
For Example :
# ipinfo 104.156.155.21
IP Status for : 104.156.155.21
IP Status : IPv4 NS Lookup (Forward) : 104.156.155.21 NS Lookup (Reverse) : None
IP Blacklisted Status : Found 104.156.155. for 104.156.155.21 [D] {Asterisk} Last Program : sshd
Ip Location Info for : 104.156.155.21
No Ip Information Found
(ie ip location lookup failed / does not exist for this ip ?)
basically the ip address block was found in my firewall so something, someone etc has tried to hack one of my servers
in the case of scom.ca i run an asterisk server and since the asterisk is noted someone tried hacking that one as well.
Basically i run a database that tracks and updates all firewall in real time.
Running FreeBSD I use PF and asterisk is linux based so i use the iptables and update every 10 minutes.
Only time now a days I get involved if a customer calls and complains they are not getting emails etc ...
That happens a few times a year.
Again just an FYI
This reply was more to indicate all email servers (and anything attached to the internet) really need to run some sort of automated ip firewall when username password hacks occur, no reverse ip address etc etc etc
Food for thought.
Have A Happy Thursday !!!
Thanks - Paul Kudla (Manager SCOM.CA Internet Services Inc.)
Scom.ca Internet Services <http://www.scom.ca> 004-1009 Byron Street South Whitby, Ontario - Canada L1N 4S3
Toronto 416.642.7266 Main 1.866.411.7266 Fax 1.888.892.7266 Email paul@scom.ca
On 11/15/2023 5:53 PM, Simon B wrote:
On Wed, 15 Nov 2023, 23:25 Michael Peddemors, <michael@linuxmagic.com>
wrote:
There is a network claiming to be a security company, however the activity appears to be a little more malicious, and appears to be attempting buffer overflows against POP-SSL services.. (and other attacks). https://www.abuseipdb.com/check/104.156.155.21 Just thought it would be worth mentioning, you might want to keep an eye out for traffic from this company... Might want to make up your own mind, or maybe someone has more information, but enough of a red flag, that thought it warranted posting on the list. Not sure yet if it is Dovecot, or the SSL libraries they are attempting to break, but using a variety of SSL/TLS methods and connections...They are not interested in dovecot per se. They scan for TLS
vulnerabilities,
mostly.
Anyone with more information? NetRange: 104.156.155.0 - 104.156.155.255 CIDR: 104.156.155.0/24 NetName: ACDRESEARCH NetHandle: NET-104-156-155-0-1 Parent: NET104 (NET-104-0-0-0-0) NetType: Direct Allocation OriginAS: Organization: Academy of Internet Research Limited Liability Company (AIRLL) RegDate: 2022-01-07 Updated: 2022-01-07 Ref: https://rdap.arin.net/registry/ip/104.156.155.0 OrgName: Academy of Internet Research Limited Liability Company OrgId: AIRLL Address: #A1- 5436 Address: 1110 Nuuanu Ave City: Honolulu StateProv: HI PostalCode: 96817 Country: US RegDate: 2021-10-15 Updated: 2022-11-06 Ref: https://rdap.arin.net/registry/entity/AIRLL --See also shadowserver.org, census.io, stretchoid, etc. All of them allegedly reputable, all of them supposedly with opt-out mechanisms, and all of them are blocked for not asking permission.
Ymmv.
Regards
Simon
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