Spoofed phishing emails bypassing all checks, delivered to mailbox

matt020191

New Member
Aug 24, 2024
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Having a really weird problem that I can't track down, and it's happening more and more often. Phishing emails with a spoofed address are making it through the gateway and delivered to the users mailbox, with the logs saying that the sender is in the user's 'welcomelist'. I double checked and the sending server is nowhere in any whitelist, let alone this user's. PMG shows the sending From as blank in the tracking center.

Code:
2025-09-25T09:06:34.556468-04:00 mxp10 postfix/smtpd[163014]: connect from 132.196.168.34.bc.googleusercontent.com[34.168.196.132]
2025-09-25T09:06:34.991387-04:00 mxp10 postfix/smtpd[163014]: F1F362028EF: client=132.196.168.34.bc.googleusercontent.com[34.168.196.132]
2025-09-25T09:06:35.144989-04:00 mxp10 postfix/cleanup[163040]: F1F362028EF: message-id=<>
2025-09-25T09:06:35.233880-04:00 mxp10 postfix/qmgr[110363]: F1F362028EF: from=<>, size=9221, nrcpt=1 (queue active)
2025-09-25T09:06:35.284917-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: new mail message-id=
2025-09-25T09:06:35.613419-04:00 mxp10 postfix/smtpd[163014]: disconnect from 132.196.168.34.bc.googleusercontent.com[34.168.196.132] ehlo=1 mail=1 rcpt=1 data=1 quit=1 commands=5
2025-09-25T09:06:35.713665-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: SA score=17/5 time=0.384 bayes=undefined autolearn=disabled hits=DMARC_QUAR(0.1),GOOG_STO_NOIMG_HTML(2.999),HTML_FONT_LOW_CONTRAST(0.001),HTML_MESSAGE(0.001),KAM_DMARC_QUARANTINE(4),KAM_DMARC_STATUS(0.01),KAM_STORAGE_GOOGLE(1.7),MIME_HTML_ONLY(0.1),MISSING_DATE(1.396),MISSING_MID(0.14),NO_FM_NAME_IP_HOSTN(0.001),RCVD_IN_SBL_CSS(3.558),RCVD_IN_XBL(0.724),RDNS_DYNAMIC(0.363),TO_EQ_FM_DIRECT_MX(0.001),TO_EQ_FM_HTML_DIRECT(1.557),TO_EQ_FM_HTML_ONLY(1.134),T_MXG_EMAIL_FRAG(0.01)
2025-09-25T09:06:35.715233-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: sender in user (sales@domain.com) welcomelist
2025-09-25T09:06:35.715515-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: sender in user (sales@domain.com) welcomelist
2025-09-25T09:06:35.715677-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: sender in user (sales@domain.com) welcomelist
2025-09-25T09:06:35.718563-04:00 mxp10 postfix/smtpd[162299]: connect from localhost.localdomain[127.0.0.1]
2025-09-25T09:06:35.720291-04:00 mxp10 postfix/smtpd[162299]: AFCC62028A5: client=localhost.localdomain[127.0.0.1], orig_client=132.196.168.34.bc.googleusercontent.com[34.168.196.132]
2025-09-25T09:06:35.762264-04:00 mxp10 postfix/cleanup[162743]: AFCC62028A5: message-id=<20250925130635.AFCC62028A5@mail.protection.domain.com>
2025-09-25T09:06:35.893099-04:00 mxp10 postfix/qmgr[110363]: AFCC62028A5: from=<>, size=10908, nrcpt=1 (queue active)
2025-09-25T09:06:35.893493-04:00 mxp10 postfix/smtpd[162299]: disconnect from localhost.localdomain[127.0.0.1] ehlo=1 xforward=1 mail=1 rcpt=1 data=1 commands=5
2025-09-25T09:06:35.893605-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: accept mail to <sales@domain.com> (AFCC62028A5) (rule: default-accept)
2025-09-25T09:06:35.905880-04:00 mxp10 pmg-smtp-filter[162968]: 2023A168D53E5B439A2: processing time: 0.616 seconds (0.384, 0.041, 0)
2025-09-25T09:06:35.906276-04:00 mxp10 postfix/lmtp[161850]: F1F362028EF: to=<sales@domain.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.1, delays=0.47/0/0.04/0.63, dsn=2.5.0, status=sent (250 2.5.0 OK (2023A168D53E5B439A2))
2025-09-25T09:06:35.906475-04:00 mxp10 postfix/qmgr[110363]: F1F362028EF: removed
2025-09-25T09:06:36.113499-04:00 mxp10 postfix/smtp[162392]: AFCC62028A5: to=<sales@domain.com>, relay=xxx.xxx.xxx.31[xxx.xxx.xxx.31]:25, delay=0.39, delays=0.17/0/0.05/0.17, dsn=2.6.0, status=sent (250 2.6.0 <20250925130635.AFCC62028A5@mail.protection.domain.com> [InternalId=122982093553748, Hostname=EX01.domain.com] 12217 bytes in 0.130, 91.369 KB/sec Queued mail for delivery)
2025-09-25T09:06:36.113801-04:00 mxp10 postfix/qmgr[110363]: AFCC62028A5: removed


And here the details of the message from the users mailbox

Code:
Received: from EX01.domain.com (xxx.xxx.xxx.160) by EX01.domain.com (xxx.xxx.xxx.160)
 with Microsoft SMTP Server (version=TLS1_2,
 cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27 via Mailbox
 Transport; Thu, 25 Sep 2025 09:06:36 -0400
DKIM-Signature: v=1; a=rsa-sha256; d=domain.com; s=2987868260;
    c=simple/simple; t=1758805596; h=from:subject:to:date:message-id;
    bh=L/h374k77EFX4BzGBOKdaKAYIGDWBV0GKBbgM3/bVEU=;
    b=UKbYHVv4NfU5Vzo4fBJ7XXa0Qb1VLw18maRfHFnU9kZIqGGLmInpgg93lW4/IVEcHCj47VhgeRl
    qQkICnoH8JI9N7Hsau4ttp1MD7DdL5ek03wWM6jKUAOoTag8R7WiQEsQQWXfrFXvAUx8SH8hNcefL
    s7JWjcmKy4pbjZsMX0x80Pi1pg1DvHETnQ64uRJlLAnHZ/FDyCq2U25DLprTUsJlNwAmxFYL3SSuR
    4Ah4cn2PmAYF3HG0XZj2QAJK8qUwYrfyoUAPlQYgtMipNje1P/Ni5XFxIjzMnJl9Azm1+2cYR7E3y
    i/hdiQVQ7cgDYfcVy660PIux4LcR4rLsHIPQ==
Received: from EX01.domain.com (xxx.xxx.xxx.160) by EX01.domain.com (xxx.xxx.xxx.160)
 with Microsoft SMTP Server (version=TLS1_2,
 cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27; Thu, 25 Sep
 2025 09:06:35 -0400
Received: from mail.protection.domain.com (xxx.xxx.xxx.31) by EX01.domain.com
 (xxx.xxx.xxx.160) with Microsoft SMTP Server (version=TLS1_2,
 cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.27 via Frontend
 Transport; Thu, 25 Sep 2025 09:06:35 -0400
Received: from mxp10.domain.com (localhost.localdomain [127.0.0.1])
    by mail.protection.domain.com (Proxmox) with ESMTP id AFCC62028A5
    for <sales@domain.com>; Thu, 25 Sep 2025 09:06:35 -0400 (EDT)
Received: from [10.88.0.4] (132.196.168.34.bc.googleusercontent.com [34.168.196.132])
    by mail.protection.domain.com (Proxmox) with ESMTP id F1F362028EF
    for <sales@domain.com>; Thu, 25 Sep 2025 09:06:34 -0400 (EDT)
Content-Type: multipart/related;
    boundary="===============2426126347014836834=="
MIME-Version: 1.0
From: "sales@domain.com" <sales@domain.com>
To: <sales@domain.com>
Subject: [EXTERNAL] Action Required Immediately
X-Priority: 2
X-SPAM-LEVEL: Spam detection results:  17
    DMARC_QUAR                0.1 DMARC quarantine policy
    GOOG_STO_NOIMG_HTML     2.999 Apparently using google content hosting to avoid URIBL
    HTML_FONT_LOW_CONTRAST  0.001 HTML font color similar or identical to background
    HTML_MESSAGE            0.001 HTML included in message
    KAM_DMARC_QUARANTINE        4 DKIM has Failed or SPF has failed on the message and the domain has a DMARC quarantine policy
    KAM_DMARC_STATUS         0.01 Test Rule for DKIM or SPF Failure with Strict Alignment
    KAM_STORAGE_GOOGLE        1.7 Google Storage API being abused by spammers
    MIME_HTML_ONLY            0.1 Message only has text/html MIME parts
    MISSING_DATE            1.396 Missing Date: header
    MISSING_MID              0.14 Missing Message-Id: header
    NO_FM_NAME_IP_HOSTN     0.001 No From name + hostname using IP address
    RCVD_IN_SBL_CSS         3.558 Received via a relay in Spamhaus SBL-CSS
    RCVD_IN_XBL             0.724 Received via a relay in Spamhaus XBL
    RDNS_DYNAMIC            0.363 Delivered to internal network by host with dynamic-looking rDNS
    TO_EQ_FM_DIRECT_MX      0.001 To == From and direct-to-MX
    TO_EQ_FM_HTML_DIRECT    1.557 To == From and HTML only, direct-to-MX
    TO_EQ_FM_HTML_ONLY      1.134 To == From and HTML only
    T_MXG_EMAIL_FRAG         0.01 URI with email in fragment
Message-ID: <20250925130635.AFCC62028A5@mail.protection.domain.com>
Date: Thu, 25 Sep 2025 09:06:35 -0400
Return-Path: <>
X-MS-Exchange-Organization-Network-Message-Id: ffba06fb-44ed-44de-426d-08ddfc345b77
X-MS-Exchange-Organization-AVStamp-Enterprise: 1.0
X-Auto-Response-Suppress: DR, OOF, AutoReply
X-MS-Exchange-Organization-AuthSource: EX01.domain.com
X-MS-Exchange-Organization-AuthAs: Anonymous
X-MS-Exchange-Transport-EndToEndLatency: 00:00:00.2609405
X-MS-Exchange-Processed-By-BccFoldering: 15.02.2562.027

Any idea why PMG would be saying the sender is in a welcomelist when 1) its empty, and 2) isn't present anywhere? Thanks!
 
Last edited:
Any idea why PMG would be saying the sender is in a welcomelist when 1) its empty, and 2) isn't present anywhere? Thanks!
The message comes from the _User_ welcome list - you can manage that for each e-mail address under GUI->Administration->User Whitelist/Welcomelist

the envelope-from (RFC5321.From) is empty, but the mail has a from header (RFC5322.From) of: From: "sales@domain.com" <sales@domain.com>

See also https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#pmgconfig_whitelist_overview

I hope this helps!