This hunt hypothesis targets adversaries leveraging the specific malicious indicators identified in the Telnyx supply chain compromise to infiltrate Azure Sentinel environments through compromised third-party dependencies. Proactively hunting for these indicators is essential because supply chain attacks often bypass traditional perimeter defenses by exploiting trusted relationships, requiring early detection of subtle anomalies before lateral movement occurs.
rule MAL_Telnyx_SupplyChain_Mar26 {
meta:
description = "Detects malicious indicators used in Telnyx supply chain attack"
author = "Marius Benthin"
date = "2026-03-28"
reference = "https://www.aikido.dev/blog/telnyx-pypi-compromised-teampcp-canisterworm"
hash = "ab4c4aebb52027bf3d2f6b2dcef593a1a2cff415774ea4711f7d6e0aa1451d4e"
score = 80
id = "73d9c3d4-7274-5278-aea3-7e921bf5d0b2"
strings:
$s1 = "bXNidWlsZC5leGU=" // msbuild.exe
$s2 = "TW96aWxsY" // Mozilla/
$s3 = ".getnframes(" // number of WAV audio frames
$s4 = "exec(base64.b64decode("
condition:
filesize < 500KB
and 3 of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 4 string patterns in its detection logic.
Here are 5 specific false positive scenarios for the “Detects malicious indicators used in Telnyx supply chain attack” rule, including suggested filters and exclusions:
Scenario: Legitimate CI/CD Pipeline Artifact Signing
openssl or gpg against expected repositories.svc-jenkins-build) executing within the designated build agent network segment (VLAN 10-Dev) and interacting with known artifact storage paths (e.g., /mnt/artifacts/*).Scenario: Scheduled Database Backup Encryption Jobs
VeeamBackupEncryptionJob) running on designated database servers (DB-Prod-01 through DB-Prod-05) during the maintenance window of 02:00–04:00 UTC.Scenario: Endpoint Antivirus Real-Time Scanning