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Mail scanner does not detect incoming Malware.

I recieved a phishing email with an attachment, the mail was classed as spam and quarantined.

I released the mail from quarantine and once I was sure it was a phising email I forwarded it to the security department at the organisation it perported to come from.

I immeadiately got a bounce from my UTM that the mail had a malware attachment !!

"Your message to the following recipients was quarantined:

<phishing@hmrc.gsi.gov.uk>, quarantine reason: Malware (Troj/DocDl-HKN)

Please contact your IT administrator for further assistance."


This means that the scanner missed it on the way in !
I have no whitelisting to prevent any antivirus scanning and use dual scan.

UTM v9.411-3

This would appear as a rather severe bug

Jeff


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  • Hi,

    what you haven't told us is your incoming mail setup.

    Do you use imap because the UTM doesn't scan imap currently only smtp and pop3.

    The malware would have been caught on the wayout by the smtp scanning.

    Please put ina feature request for imap scanning.

    XG115W - v20 GA - Home

    XG on VM 8 - v20 GA

    If a post solves your question please use the 'Verify Answer' button.

  • Sorry,

    Came in via SMTP Proxy

    Was marked as spam, when I released it and forwarded I got the message.

     

    Log:

    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:50:51 firewall exim-in[7784]: 2017-02-15 13:50:51 H=(hmrcg0v.co.uk) [146.20.65.136]:54525 Warning: jimbojones.com profile excludes greylisting: Skipping greylisting for this message
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:50:51 firewall exim-in[7784]: 2017-02-15 13:50:51 H=(hmrcg0v.co.uk) [146.20.65.136]:54525 Warning: jimbojones.com profile excludes SANDBOX scan
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:50:52 firewall exim-in[7784]: 2017-02-15 13:50:52 [146.20.65.136] F=<service-jimbo=jimbojones.com@hmrcg0v.co.uk> R=<jimbo@jimbojones.com> Verifying recipient address with callout
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:51:13 firewall exim-in[7784]: 2017-02-15 13:51:13 1cdzyu-00021Y-1J DKIM: d=hmrcg0v.co.uk s=key c=relaxed/relaxed a=rsa-sha1 [invalid - public key record (currently?) unavailable]
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:51:14 firewall exim-in[7784]: 2017-02-15 13:51:14 1cdzyu-00021Y-1J <= service-jimbo=jimbojones.com@hmrcg0v.co.uk H=(hmrcg0v.co.uk) [146.20.65.136]:54525 P=esmtp S=146907 id=0.0.0.0.1D287917DA14CAC.1AC5FEA0@hmrcg0v.co.uk
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:51:14 firewall exim-in[7784]: 2017-02-15 13:51:14 SMTP connection from (hmrcg0v.co.uk) [146.20.65.136]:54525 closed by QUIT
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:51:20 firewall smtpd[7932]: SCANNER[7932]: 1cdzzM-00023w-Dv <= service-jimbo=jimbojones.com@hmrcg0v.co.uk R=1cdzyu-00021Y-1J P=INPUT S=145531
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-13:51:20 firewall smtpd[7932]: SCANNER[7932]: id="1001" severity="info" sys="SecureMail" sub="smtp" name="email quarantined" srcip="146.20.65.136" from="service-jimbo=jimbojones.com@hmrcg0v.co.uk" to="jimbo@jimbojones.com" subject="HMRC Secure Communication" queueid="1cdzzM-00023w-Dv" size="145531" reason="as" extra=""
    /var/log/smtp/2017/02/smtp-2017-02-15.log.gz:2017:02:15-23:03:00 firewall exim-out[8786]: 2017-02-15 23:03:00 1cdzzM-00023w-Dv => jimbo@jimbojones.com P=<service-jimbo=jimbojones.com@hmrcg0v.co.uk> R=static_route_hostlist T=static_smtp H=My.LAN.IP.2 [My.LAN.IP.2]:25 C="250 2.0.0 Ok: queued as 929496086CE0"

  • Hi Billybob

    Sophos AV detects it on my desktop, I had to disable on Access AV scanning temporarily to upload it to Sophos

  • Aha, I get it now. Are you using endpoint protection or a standalone subscription. In either case a virustotal.com test will still be interesting even if it is a false positive.

  • Hi Billybob

    I use Endpoint protection that is provided free with UTM 9, the mail proxy is handled by the UTM but I had to save the file from the email in order to submit to sophos, this is when endpoint kicked in. so I disabled OAS sent the sample deleted and re enabled OAS

    Jeff

  • Thats ok. I remember when endpoint protection was first introduced,  did a lot of tests for endpoint protection vs UTM protection and he found results similar to yours. Some of the problems were fixed after his discoveries but sadly, now I see the quality of UTM detection is slipping again[:@] In any case thanks for the heads up.

     

    Edit: A false positive; which was my first inclination. Have taken out sophos bashing after Bob's findings below[:D]

  • UTM Endpoint on my laptop did not see anything bad, nor did virustotal.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
  • Thanks for taking the time Bob. I don't know what we would do without you[:D] I have edited my post above accordingly[;)]

  • Hi Bob and Billybob,

    Thanks for the help but am a bit confused

    Are you saying this is a false positive that has been detected by both OAS and outgoing mail scanner ?

    Jeff

  • I don't know, Jeff.  I don't understand what happened to cleanse the message when it was forwarded to me, but that appears to be what happened.  Very strange.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
  • Hi Bob,

    OK Thanks, I did open the file you returned to me. There were no alarms from UTM or Sophos Endpoint OAS but there was no content in the file.

    To check I tried to open the original and it still triggered the OAS as a virus.

    Jeff

  • Wow, now that's some nifty malware, Jeff.  You might need to send the entire mail as an attachment instead of forwarding it.  Try sending it to me that way.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
Reply
  • Wow, now that's some nifty malware, Jeff.  You might need to send the entire mail as an attachment instead of forwarding it.  Try sending it to me that way.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
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