We block, have for years and years.. Richard Strittmatter
From: Af [mailto:af-boun...@afmug.com] On Behalf Of Mike Hammett Sent: Monday, September 19, 2016 11:59 AM To: af@afmug.com Subject: Re: [AFMUG] everyone should be blocking SMB ports Yes, block. ----- Mike Hammett Intelligent Computing Solutions<http://www.ics-il.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/ICSIL>[http://www.ics-il.com/images/googleicon.png]<https://plus.google.com/+IntelligentComputingSolutionsDeKalb>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/intelligent-computing-solutions>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/ICSIL> Midwest Internet Exchange<http://www.midwest-ix.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/mdwestix>[http://www.ics-il.com/images/linkedinicon.png]<https://www.linkedin.com/company/midwest-internet-exchange>[http://www.ics-il.com/images/twittericon.png]<https://twitter.com/mdwestix> The Brothers WISP<http://www.thebrotherswisp.com/> [http://www.ics-il.com/images/fbicon.png]<https://www.facebook.com/thebrotherswisp>[http://www.ics-il.com/images/youtubeicon.png] <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> ________________________________ From: "That One Guy /sarcasm" <thatoneguyst...@gmail.com<mailto:thatoneguyst...@gmail.com>> To: af@afmug.com<mailto:af@afmug.com> Sent: Monday, September 19, 2016 11:57:44 AM Subject: Re: [AFMUG] everyone should be blocking SMB ports Whats the WISP consensus on blocking those ports at the edge? also, whats the best religion? if Ford or Chevy better? Whats the greatest sports team? On Mon, Sep 19, 2016 at 11:50 AM, Zach Underwood <zunder1...@gmail.com<mailto:zunder1...@gmail.com>> wrote: My work has its own IP address and get upstream from atnt and charter. The smb ports are not blocked. Zach Underwood (RHCE,RHCSA,RHCT,UACA) http://ZachUnderwood.me advance-networking.com<http://advance-networking.com> On Sep 19, 2016 12:47 PM, "Josh Luthman" <j...@imaginenetworksllc.com<mailto:j...@imaginenetworksllc.com>> wrote: Cable/Telco probably. WISP? I dunno... Josh Luthman Office: 937-552-2340<tel:937-552-2340> Direct: 937-552-2343<tel:937-552-2343> 1100 Wayne St Suite 1337 Troy, OH 45373 On Mon, Sep 19, 2016 at 12:47 PM, Sean Heskett <af...@zirkel.us<mailto:af...@zirkel.us>> wrote: i think everyone has been blocking those ports since 1998-ish (or at least you should be) -sean On Mon, Sep 19, 2016 at 10:22 AM, Zach Underwood <zunder1...@gmail.com<mailto:zunder1...@gmail.com>> wrote: This was written from the view point of windows AD setup can affect home users too since MS makes people use MS live accounts to log in to windows. Problem: Outside servers can get username/domain/password hash. Once a remote server has the login info they could connect to VPN, Office365 or an other service that using AD domain user info. See attachment for example. I got the example from a VM with a test account on it. Details: Microsoft based browsers like IE and Edge can be induced to make a outbound smb connection to a remote server. In this connection Microsoft will send over username, domain, and password hash. The remote server then can do a decryption of the password hash using brute force, password, dictionary and rainbow tables. Fix: The fastest way to stop this is to block all of the smb networks ports on the edge firewall for incoming and outgoing. The ports are 137-138udp, 137tcp,139tcp, 445tcp Sources: http://www.zdnet.com/article/windows-attack-can-steal-your-username-password-and-other-logins/ Testing site: https://msleak.perfect-privacy.com/ -- Zach Underwood (RHCE,RHCSA,RHCT,UACA) My website<http://zachunderwood.me> advance-networking.com<http://advance-networking.com> -- If you only see yourself as part of the team but you don't see your team as part of yourself you have already failed as part of the team.
