Security Basics mailing list archives
Re: email address "spoofed"
From: "Webb Wang CS" <webb.wang () cybershieldnetworks com>
Date: Mon, 8 Mar 2004 14:27:27 -0500
Tim, Feels like your SMTP server got open relay enabled. Just by examining your message header, it reported message was from your email server. Depending on your server setting, anybody can manually telnet to your server on port 25 and craft out a message with fake 'from' field and have it sent out to a legit account. To close up this hole, we usually do one or more of the following: (1) disable open relay feature at the server (2) require authentication on user account before allowing message sending (3) make sure a successful email retrieval (or POP) before allowing sending message with the user account (4) force a DNS reverse look up to ensure the remote site has a legit DNS record. My 2 cents, Webb ---- I'm not sure if "spoofing" is the correct term but here is what has happened: Someone is sending out email messages (with virus laden attachments) using our domain name ... they are addressed as coming from support () ourdomainname com (ourdomainame would be our actual domain name) which is an email address that we never set up. My question is how is this done and is there anything we can do to prevent this in the future? The message header looks like this: Received: from your-xhtr8hvc4p [68.55.1.207] by ourdomainname.com (SMTPD32-8.05) id A3C8DF0118; Fri, 05 Mar 2004 04:09:28 -0500 Date: Fri, 05 Mar 2004 04:07:07 -0500 To: info () ourdomainname com Subject: E-mail account security warning. From: support () ourdomainname com Message-ID: <oruybbfoofisdsegtve () ourdomainname com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="--------hggfurquvkrsejwodibt" X-RCPT-TO: <info () ourdomainname com> Status: U X-UIDL: 355598192 Tim --------------------------------------------------------------------------- Ethical Hacking at the InfoSec Institute. Mention this ad and get $545 off any course! All of our class sizes are guaranteed to be 10 students or less to facilitate one-on-one interaction with one of our expert instructors. Attend a course taught by an expert instructor with years of in-the-field pen testing experience in our state of the art hacking lab. Master the skills of an Ethical Hacker to better assess the security of your organization. Visit us at: http://www.infosecinstitute.com/courses/ethical_hacking_training.html ---------------------------------------------------------------------------- --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.600 / Virus Database: 381 - Release Date: 2/28/2004 --------------------------------------------------------------------------- Ethical Hacking at the InfoSec Institute. Mention this ad and get $545 off any course! All of our class sizes are guaranteed to be 10 students or less to facilitate one-on-one interaction with one of our expert instructors. Attend a course taught by an expert instructor with years of in-the-field pen testing experience in our state of the art hacking lab. Master the skills of an Ethical Hacker to better assess the security of your organization. Visit us at: http://www.infosecinstitute.com/courses/ethical_hacking_training.html ----------------------------------------------------------------------------
Current thread:
- RE: email address "spoofed", (continued)
- RE: email address "spoofed" Aditya, ALD [Aditya Lalit Deshmukh] (Mar 15)
- RE: email address "spoofed" David Gillett (Mar 15)
- Re: email address "spoofed" pablo gietz (Mar 08)
- Re: email address "spoofed" Torry Crass (Mar 08)
- RE: email address "spoofed" Panagiotis (Mar 09)
- Re: email address "spoofed" AgfTech Lists (Mar 09)
- Re: email address "spoofed" Luis E. Alvarado Day (Mar 09)
- Re: email address "spoofed" Adrian Hall (Mar 11)
- RE: email address "spoofed" Chinnery, Paul (Mar 08)
- Re: email address "spoofed" Sean Earp (Mar 08)
- Re: email address "spoofed" Webb Wang CS (Mar 08)
- RE: email address "spoofed" Jeff McLaughlin (Mar 08)
- RE: email address "spoofed" Phil Waller (Mar 08)
- RE: email address "spoofed" Fields, James (Mar 08)
- RE: email address "spoofed" Josh Mills (Mar 09)
- RE: email address "spoofed" JULIO CALDERON (Mar 12)