mgeeky/decode-spam-headersUn script que te ayuda a entender por qué tu correo electrónico terminó en Spam
Ya sea que estés tratando de entender por qué un correo electrónico específico terminó en SPAM/Correo no deseado para tus tareas administrativas diarias o para tus propósitos de simulación de phishing Red-Team, ¡este script está ahí para ayudarte!
La idea surgió al realizar ejercicios comerciales de simulación de phishing contra un entorno MS Office365 E5, equipado con MS Defender for Office365. Como uno puede imaginar, un stack de seguridad bastante difícil de manejar desde una perspectiva de simulación de phishing. Después de revisar manualmente todos estos encabezados SMTP de Office365 e intentar seleccionar los valores SCL, llegó el momento de escribir un parser adecuado para encabezados SMTP.
El tiempo pasó y fui añadiendo soporte para más y más encabezados SMTP - y aquí lo tenemos. Una herramienta que ahora comprende decenas de encabezados diferentes.
Esta herramienta acepta como entrada un archivo *.EML o *.txt con todos los encabezados SMTP. Luego extraerá un subconjunto de encabezados interesantes y, mediante 105+ pruebas, intentará decodificarlos tanto como sea posible.
Este script también extrae todas las direcciones IPv4 y nombres de dominio, y realiza una resolución DNS completa de los mismos.
La salida resultante contendrá información útil sobre por qué este correo electrónico podría haber sido bloqueado.
Para embellecer tu código HTML de phishing antes de enviarlo a tu cliente, es posible que también quieras pasárselo a mi phishing-HTML-linter.py. Hace un trabajo bastante decente encontrando malos olores en tu HTML que harán que tu correo tenga un aumento en la puntuación de spam.
Received correctamente analizados):
py decode-spam-headers.py headers.txt -f html -o report.html ):
Encabezados procesados (se analizan más de 85+ encabezados):
X-forefront-antispam-reportX-exchange-antispamX-exchange-antispam-mailbox-deliveryX-exchange-antispam-message-infoX-microsoft-antispam-report-cfa-testReceivedFromToSubjectThread-topicReceived-spfX-mailerX-originating-ipUser-agentLa mayoría de estos encabezados no están completamente documentados, por lo que el script no puede precisar todos los detalles, pero al menos recopila todo lo que pude encontrar sobre ellos.
(5) Test: X-Forefront-Antispam-Report
HEADER: X-Forefront-Antispam-Report
VALUE: CIP:209.85.167.100;CTRY:US;LANG:de;SCL:5;SRV:;IPV:NLI;SFV:SPM;H:mail-lf1-f100.google.com;PTR:mail-l f1-f100.google.com;CAT:DIMP;SFTY:9.19;SFS:(4636009)(956004)(166002)(6916009)(356005)(336012)(19 625305002)(22186003)(5660300002)(4744005)(6666004)(35100500006)(82960400001)(26005)(7596003)(7636003)(554460 02)(224303003)(1096003)(58800400005)(86362001)(9686003)(43540500002);DIR:INB;SFTY:9.19;
[...]
- Message matched 24 Anti-Spam rules (SFS): <============ opaque anti-spam rules
- (1096003)
- (166002)
- (19625305002)
- (22186003)
- (224303003)
- (26005)
- (336012)
- (356005)
- (35100500006) - (SPAM) Message contained embedded image.
El proceso es puramente manual y recurre al envío de correos diseñados específicamente a los servidores de correo de Office365, y luego a la revisión y correlación manual de las reglas recopiladas.
Habiendo enviado ya más de 60 correos, esto es lo que puedo decir hasta ahora sobre las reglas de Microsoft:```py
#
# Below rules were collected solely in a trial-and-error manner or by scraping any
# pieces of information from all around the Internet.
#
# They do not represent the actual Anti-Spam rule name or context and surely represent
# something close to what is understood (or they may have totally different meaning).
#
# Until we'll be able to review anti-spam rules documention, there is no viable mean to map
# rule ID to its meaning.
#
Anti_Spam_Rules_ReverseEngineered = \
{
'35100500006' : logger.colored('(SPAM) Message contained embedded image.', 'red'),
# https://docs.microsoft.com/en-us/answers/questions/416100/what-is-meanings-of-39x-microsoft-antispam-mailbox.html
'520007050' : logger.colored('(SPAM) Moved message to Spam and created Email Rule to move messages from this particular sender to Junk.', 'red'),
# triggered on an empty mail with subject being: "test123 - viagra"
'162623004' : 'Subject line contained suspicious words (like Viagra).',
# triggered on mail with subject "test123" and body being single word "viagra"
'19618925003' : 'Mail body contained suspicious words (like Viagra).',
# triggered on mail with empty body and subject "Click here"
'28233001' : 'Subject line contained suspicious words luring action (ex. "Click here"). ',
# triggered on a mail with test subject and 1500 words of http://nietzsche-ipsum.com/
'30864003' : 'Mail body contained a lot of text (more than 10.000 characters).',
# mails that had simple message such as "Hello world" triggered this rule, whereas mails with
# more than 150 words did not.
'564344004' : 'HTML mail body with less than 150 words of text (not sure how much less though)',
# message was sent with a basic html and only one <u> tag in body.
'67856001' : 'HTML mail body contained underline <u> tag.',
# message with html,head,body and body containing simple text with no b/i/u formatting.
'579124003' : 'HTML mail body contained text, but no text formatting (<b>, <i>, <u>) was present',
# This is a strong signal. Mails without <a> doesnt have this rule.
'166002' : 'HTML mail body contained URL <a> link.',
# Message contained <a href="https://something.com/file.html?parameter=value" - GET parameter with value.
'21615005' : 'Mail body contained <a> tag with URL containing GET parameter: ex. href="https://foo.bar/file?aaa=bbb"',
# Message contained <a href="https://something.com/file.html?parameter=https://another.com/website"
# - GET parameter with value, being a URL to another website
'45080400002' : 'Something about <a> tag\'s URL. Possibly it contained GET parameter with value of another URL: ex. href="https://foo.bar/file?aaa=https://baz.xyz/"',
# Message contained <a> with href pointing to a file with dangerous extension, such as file.exe
'460985005' : 'Mail body contained HTML <a> tag with href URL pointing to a file with dangerous extension (such as .exe)',
#
# Message1: GoPhish -> VPS 587/tcp redirector -> smtp.gmail.com:587 -> target
# Message2: GoPhish -> VPS 587/tcp redirector -> smtp-relay.gmail.com:587 -> target
#
# These were the only differences I spotted:
# Message1 - FirstHop Gmail SMTP Received with ESMTPS.
# Message2 - FirstHop Gmail SMTP-Relay Received with ESMTPSA.
#
'121216002' : 'First Hop MTA SMTP Server used as a SMTP Relay. It\'s known to originate e-mails, but here it acted as a Relay. Or maybe due to use of "with ESMTPSA" instead of ESMTPS?',
# Triggered on message with <a> added to HTML: <a href="https://support.spotify.com/is-en/">https://www.reddit.com/</a>
'966005' : 'Mail body contained link tag with potentially masqueraded URL: <a href="https://attacker.com">https://example.com</a>',
#
# Message1: GoPhish EC2 -> another EC2 with socat to smtp.gmail.com:587 (authenticated) -> Target
# Message2: GoPhish EC2 -> Gsuite -> Target
#
# Subject, mail body were exactly the same.
#
# Below two rules were added to the second message. My understanding is that they're somehow referring
# to the reputation of the first-hop server, maybe reverse-DNS resolution.
#
'5002400100002' : "(GUESSING) Somehow related to First Hop server reputation, it's reverse-PTR resolution or domain impersonation",
'58800400005' : "(GUESSING) Somehow related to First Hop server reputation, it's reverse-PTR resolution or domain impersonation",
'19625305002' : '(GUESSING) Something to do with the HTML code and used tags/structures',
'43540500002' : '(GUESSING) Something to do with the HTML code and used tags/structures',
'460985005' : '(GUESSING) Something to do with either more-complex HTML code or with the <a> tag and its URL.',
# Triggered on an empty text message, subject "test" - that was marked with "Domain Impersonation", however
# ForeFront Anti-Spam headers did not support that Domain Impersonation. Weird.
'22186003' : '(GUESSING) Something to do with either Text message (non-HTML) or probable Domain Impersonation',
# Found by @ipSlav (https://github.com/mgeeky/decode-spam-headers/issues/15)
'42882007' : 'Missing Reply-To Address. Might be fixed by adding -ReplyTo flag to Send-MailMessage',
'78352004' : 'Missing Reply-To Address. Might be fixed by adding -ReplyTo flag to Send-MailMessage',
}
Si sabes de alguna otra regla anti-spam de Office365 (o tienes sugerencias para las descritas anteriormente) - házmelo saber en los issues de este repo y lo añadiré enseguida :)
Instala las dependencias de Python3 necesarias antes del primer uso:``` bash$ pip3 install -r requirements.txt
Ayuda:```
PS> py .\decode-spam-headers.py --help
usage: decode-spam-headers.py [options] <file | --list tests>
optional arguments:
-h, --help show this help message and exit
Required arguments:
infile Input file to be analysed or --list tests to show available tests.
Options:
-o OUTFILE, --outfile OUTFILE
Output file with report
-f {json,text,html}, --format {json,text,html}
Analysis report format. JSON, text. Default: text
-N, --nocolor Dont use colors in text output.
-v, --verbose Verbose mode.
-d, --debug Debug mode.
-l, --list List available tests and quit. Use it like so: --list tests
Tests:
-i tests, --include-tests tests
Comma-separated list of test IDs to run. Ex. --include-tests 1,3,7
-e tests, --exclude-tests tests
Comma-separated list of test IDs to skip. Ex. --exclude-tests 1,3,7
-r, --resolve Resolve IPv4 addresses / Domain names.
-R, --dont-resolve Do not resolve anything.
-a, --decode-all Decode all =?us-ascii?Q? mail encoded messages and print their contents.
Si quieres ejecutar solo un subconjunto de pruebas, primero necesitarás conocer los Test IDs que elegir.
Ejecuta el script con -l tests para obtener esa lista.
Lista las pruebas disponibles y sus IDs correspondientes:``` C:> py decode-spam-headers.py -l tests
[.] Available tests:
TEST_ID - TEST_NAME
--------------------------------------
1 - Received - Mail Servers Flow
2 - Extracted IP addresses
3 - Extracted Domains
4 - Bad Keywords In Headers
5 - Sender Address Analysis
6 - Subject and Thread Topic Difference
7 - Authentication-Results
8 - ARC-Authentication-Results
9 - Received-SPF
10 - Mail Client Version
11 - User-Agent Version
12 - X-Forefront-Antispam-Report
13 - X-MS-Exchange-Organization-SCL
14 - X-Microsoft-Antispam-Mailbox-Delivery
15 - X-Microsoft-Antispam Bulk Mail
16 - X-Exchange-Antispam-Report-CFA-Test
17 - Domain Impersonation
18 - SpamAssassin Spam Status
19 - SpamAssassin Spam Level
20 - SpamAssassin Spam Flag
21 - SpamAssassin Spam Report
22 - OVH's X-VR-SPAMCAUSE
23 - OVH's X-Ovh-Spam-Reason
24 - OVH's X-Ovh-Spam-Score
25 - X-Virus-Scan
26 - X-Spam-Checker-Version
27 - X-IronPort-AV
28 - X-IronPort-Anti-Spam-Filtered
29 - X-IronPort-Anti-Spam-Result
30 - X-Mimecast-Spam-Score
31 - Spam Diagnostics Metadata
32 - MS Defender ATP Message Properties
33 - Message Feedback Loop
34 - End-to-End Latency - Message Delivery Time
36 - X-IP-Spam-Verdict
37 - X-Amp-Result
38 - X-IronPort-RemoteIP
39 - X-IronPort-Reputation
40 - X-SBRS
41 - X-IronPort-SenderGroup
42 - X-Policy
43 - X-IronPort-MailFlowPolicy
44 - X-SEA-Spam
45 - X-FireEye
46 - X-AntiAbuse
47 - X-TMASE-Version
48 - X-TM-AS-Product-Ver
49 - X-TM-AS-Result
50 - X-IMSS-Scan-Details
51 - X-TM-AS-User-Approved-Sender
52 - X-TM-AS-User-Blocked-Sender
53 - X-TMASE-Result
54 - X-TMASE-SNAP-Result
55 - X-IMSS-DKIM-White-List
56 - X-TM-AS-Result-Xfilter
57 - X-TM-AS-SMTP
58 - X-TMASE-SNAP-Result
59 - X-TM-Authentication-Results
60 - X-Scanned-By
61 - X-Mimecast-Spam-Signature
62 - X-Mimecast-Bulk-Signature
63 - X-Forefront-Antispam-Report-Untrusted
64 - X-Microsoft-Antispam-Untrusted
65 - X-Mimecast-Impersonation-Protect
66 - X-Proofpoint-Spam-Details
67 - X-Proofpoint-Virus-Version
68 - SPFCheck
69 - X-Barracuda-Spam-Score
70 - X-Barracuda-Spam-Status
71 - X-Barracuda-Spam-Report
72 - X-Barracuda-Bayes
73 - X-Barracuda-Start-Time
74 - Similar to SpamAssassin Spam Level headers
75 - SMTP Header Contained IP address
76 - Other unrecognized Spam Related Headers
77 - Other interesting headers
78 - Security Appliances Spotted
79 - Email Providers Infrastructure Clues
80 - X-Microsoft-Antispam-Message-Info (use -a to show its results)
81 - Decoded Mail-encoded header values (use -a to show its results)
82 - Header Containing Client IP
83 - Office365 Tenant ID
84 - Organization Name
85 - MS Defender for Office365 Safe Links Version
86 - Suspicious Words in Headers
87 - AWS SES Outgoing
88 - IronPort-Data
89 - IronPort-HdrOrder
90 - X-DKIM
91 - DKIM-Filter
92 - X-SpamExperts-Class
93 - X-SpamExperts-Evidence
94 - X-Recommended-Action
95 - X-AppInfo
96 - X-Spam
97 - X-TM-AS-MatchedID
98 - MTA Hostname Exposed
99 - Office365 First Contact Safety Tip
100 - EOP - Bypass Focused Inbox
101 - EOP - Enhanced Filtering - SkipListedInternetSender
102 - EOP - Enhanced Filtering - ExternalOriginalInternetSender
103 - Cloudmark Analysis
104 - The Real Sender - via Authenticated-Sender
105 - Identified Sender Addresses
106 - Unsual SMTP headers
### Informe HTML
Para generar el informe HTML - utilice los siguientes parámetros:```
PS> py decode-spam-headers.py headers.txt -f html -o report.html
Ejemplo de ejecución (la estructura y el contenido de la salida provienen de una versión desactualizada del script):``` PS> py decode-spam-headers.py headers.txt
(1) Test: Received - Mail Servers Flow
HEADER: Received
VALUE: ...
ANALYSIS: - List of server hops used to deliver message:
--> (1) "attacker" <[email protected]>
|_> (2) SMTP-SERVICE (44.55.66.77)
time: 01 Jan 2021 12:34:20
|_> (3) mail-wr1-f51.google.com (209.85.221.51)
time: 01 Jan 2021 12:34:20
version: fuzzy match: Exchange Server 2019 CU11; October 12, 2021; 15.2.986.9
|_> (4) SN1NAM02FT0061.eop-nam02.prod.protection.outlook.com (2603:10b6:806:131:cafe::e5)
time: 01 Jan 2021 12:34:20
version: fuzzy match: Exchange Server 2019 CU11; October 12, 2021; 15.2.986.9
|_> (5) SA0PR11CA0138.namprd11.prod.outlook.com (2603:10b6:806:131::23)
time: 01 Jan 2021 12:34:20
version: fuzzy match: Exchange Server 2019 CU11; October 12, 2021; 15.2.986.9
|_> (6) CP2PR80MB4114.lamprd80.prod.outlook.com (2603:10d6:102:3c::15)
time: 01 Jan 2021 12:34:23
|_> (7) "Victim Surname" <[email protected]>
[...]
(4) Test: Mail Client Version
HEADER: X-Mailer
VALUE: OEM
ANALYSIS: - X-Mailer header was present and contained value: "OEM".
(5) Test: X-Forefront-Antispam-Report
HEADER: X-Forefront-Antispam-Report
VALUE: CIP:209.85.167.100;CTRY:US;LANG:de;SCL:5;SRV:;IPV:NLI;SFV:SPM;H:mail-lf1-f100.google.com;PTR:mail-l f1-f100.google.com;CAT:DIMP;SFTY:9.19;SFS:(4636009)(956004)(166002)(6916009)(356005)(336012)(19 625305002)(22186003)(5660300002)(4744005)(6666004)(35100500006)(82960400001)(26005)(7596003)(7636003)(554460 02)(224303003)(1096003)(58800400005)(86362001)(9686003)(43540500002);DIR:INB;SFTY:9.19;
ANALYSIS: - Microsoft Office365/Exchange ForeFront Anti-Spam report
- CIP: Connecting IP address: 209.85.167.100
- CTRY: The source country as determined by the connecting IP address
- US
- LANG: The language in which the message was written
- de
- IPV: Ingress Peer Verification status
- NLI: The IP address was not found on any IP reputation list.
- SFV: Message Filtering
- SPM: The message was marked as spam by spam filtering.
- H: The HELO or EHLO string of the connecting email server.
- mail-lf1-f100.google.com
- PTR: Reverse DNS of the Connecting IP peer's address
- mail-lf1-f100.google.com
- CAT: The category of protection policy
- DIMP: Domain Impersonation
- SFTY: The message was identified as phishing
- 9.19: Domain impersonation. The sending domain is attempting to impersonate a protected domain
- DIR: Direction of email verification
- INB: Inbound email verification
- Message matched 24 Anti-Spam rules (SFS):
- (1096003)
- (166002)
- (19625305002)
- (22186003)
- (224303003)
- (26005)
- (336012)
- (356005)
- (35100500006) - (SPAM) Message contained embedded image.
- (43540500002)
- (4636009)
- (4744005)
- (55446002)
- (5660300002)
- (58800400005)
- (6666004)
- (6916009)
- (7596003)
- (7636003)
- (82960400001)
- (86362001)
- (956004)
- (9686003)
- SCL: Spam Confidence Level: 5
- SPAM: Spam filtering marked the message as Spam
More information: - https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/anti-spam-message-headers - https://docs.microsoft.com/en-us/exchange/antispam-and-antimalware/antispam-protection/antispam-stamps - https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/spam-confidence-levels - https://docs.microsoft.com/en-us/exchange/monitoring/trace-an-email-message/run-a-message-trace-and-view-results
(6) Test: X-Microsoft-Antispam-Mailbox-Delivery
HEADER: X-Microsoft-Antispam-Mailbox-Delivery
VALUE: ucf:0;jmr:1;auth:0;dest:J;ENG:(910001)(944506458)(944626604)(750132)(520011016);
ANALYSIS: - This header denotes what to do with received message, where to put it.
- auth: Message originating from Authenticated sender
- 0: Not Authenticated
- dest: Destination where message should be placed
- J: JUNK directory
- Message matched 6 Anti-Spam Delivery rules:
- (520011016)
- (750132)
- (910001)
- (944506458)
- (944626604)
(7) Test: X-Microsoft-Antispam Bulk Mail
HEADER: X-Microsoft-Antispam VALUE: BCL:0;
ANALYSIS: - BCL: BULK Confidence Level: 0 The message isn't from a bulk sender.
More information:
- https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/bulk-complaint-level-values
[...]
(10) Test: MS Defender ATP Message Properties
HEADER: X-MS-Exchange-AtpMessageProperties
VALUE: SA|SL
ANALYSIS: - MS Defender Advanced Threat Protection enabled following protections on this message: - Safe Attachments Protection - Safe Links Protection
(11) Test: Domain Impersonation
HEADER: From
VALUE: "attacker" [email protected]
ANALYSIS: - Mail From: [email protected]
- Mail Domain: attacker.com
--> resolves to: 11.22.33.44
--> reverse-DNS resolves to: ec2-11-22-33-44.eu-west-3.compute.amazonaws.com
(sender's domain: amazonaws.com)
- First Hop: SMTP-SERVICE (44.55.66.77)
--> resolves to:
--> reverse-DNS resolves to: host44-55-66-77.static.arubacloud.pl
(first hop's domain: arubacloud.pl)
- Domain SPF: "v=spf1 include:_spf.google.com ~all"
- WARNING! Potential Domain Impersonation!
- Mail's domain should resolve to: amazonaws.com
- But instead first hop resolved to: arubacloud.pl
---
### Créditos
- [ipSlav](https://github.com/ipSlav) - por [identificar dos reglas opacas de Office365](https://github.com/mgeeky/decode-spam-headers/issues/15): `42882007` y `78352004`
---
### Problemas Conocidos
- El método `getOffice365TenantNameById(tenantID)` aún no está terminado; conozco algunas formas de mapear el GUID de inquilino de Office365 al nombre de inquilino, pero aún no he podido establecer una forma estable de hacerlo.
- La cabecera `Authentication-Results` aún no está completamente analizada: hay que incluir el procesamiento de `reason` y otros campos según la [documentación de Microsoft](https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/anti-spam-message-headers?view=o365-worldwide)
---
### ☕ Muestra tu Apoyo ☕
Este y otros proyectos son el resultado de noches sin dormir y **mucho trabajo duro**. Si te gusta lo que hago y aprecias que siempre devuelvo algo a la comunidad,
[Considera invitarme a un café](https://github.com/sponsors/mgeeky) _(o mejor una cerveza)_ solo para decir ¡gracias! 💪
---```
Mariusz Banach / mgeeky, (@mariuszbit)
<mb [at] binary-offensive.com>
X-forefront-antispam-reportX-microsoft-antispam-mailbox-deliveryX-microsoft-antispamX-exchange-antispam-report-cfa-testX-spam-statusX-spam-levelX-spam-flagX-spam-reportX-vr-spamcauseX-ovh-spam-reasonX-vr-spamscoreX-virus-scannedX-spam-checker-versionX-ironport-avX-ironport-anti-spam-filteredX-ironport-anti-spam-resultX-mimecast-spam-scoreSpamdiagnosticmetadataX-ms-exchange-atpmessagepropertiesX-msfblX-ms-exchange-transport-endtoendlatencyX-ms-oob-tlc-oobclassifiersX-ip-spam-verdictX-amp-resultX-ironport-remoteipX-ironport-reputationX-sbrsX-ironport-sendergroupX-policyX-ironport-mailflowpolicyX-remote-ipX-sea-spamX-fireeyeX-antiabuseX-tmase-versionX-tm-as-product-verX-tm-as-resultX-imss-scan-detailsX-tm-as-user-approved-senderX-tm-as-user-blocked-senderX-tmase-resultX-tmase-snap-resultX-imss-dkim-white-listX-tm-as-result-xfilterX-tm-as-smtpX-scanned-byX-mimecast-spam-signatureX-mimecast-bulk-signatureX-sender-ipX-forefront-antispam-report-untrustedX-microsoft-antispam-untrustedX-sophos-senderhistoryX-sophos-rescanX-MS-Exchange-CrossTenant-IdX-OriginatorOrgIronPort-DataIronPort-HdrOrdrX-DKIMDKIM-FilterX-SpamExperts-ClassX-SpamExperts-EvidenceX-Recommended-ActionX-AppInfoX-SpamX-TM-AS-MatchedIDX-MS-Exchange-EnableFirstContactSafetyTipX-MS-Exchange-Organization-BypassFocusedInboxX-MS-Exchange-SkipListedInternetSenderX-MS-Exchange-ExternalOriginalInternetSenderX-CNFS-AnalysisX-Authenticated-SenderX-Apparently-FromX-Env-SenderSender