Suspicious Telegram API Access (via proxy)

title: Suspicious Telegram API Access (via proxy)
id: 8c2e59f4-2fb3-528b-aa7c-9f9d299cebab
status: stable
description: This rule detects anomalous requests to Telegram API without the usual Telegram User-Agent
references:
    - https://attack.mitre.org/techniques/T1102/002/
    - https://attack.mitre.org/techniques/T1071/001/
    - https://researchcenter.paloaltonetworks.com/2018/03/unit42-telerat-another-android-trojan-leveraging-telegrams-bot-api-to-target-iranian-users/
    - https://blog.malwarebytes.com/threat-analysis/2016/11/telecrypt-the-ransomware-abusing-telegram-api-defeated/
    - https://www.welivesecurity.com/2016/12/13/rise-telebots-analyzing-disruptive-killdisk-attacks/
author: Huntrule Team
date: 2026-01-18
tags:
    - attack.command-and-control
    - attack.t1071.001
    - attack.t1102.002
logsource:
    category: proxy
detection:
    selection:
        cs-host: 'api.telegram.org'
    filter:
        c-useragent|contains:
            - 'Telegram'
            - 'Bot'
    condition: selection and not filter
falsepositives:
    - Unknown
level: medium