title: Telegram API Access
id: b494b165-6634-483d-8c47-2026a6c52372
status: experimental
description: Detects suspicious requests to Telegram API without the usual Telegram User-Agent
author: Florian Roth
date: 2018/06/05
modified: 2020/09/03
references:
    - 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/
logsource:
    category: proxy
detection:
    selection:
        r-dns: 
            - 'api.telegram.org'  # Often used by Bots
    filter:
        c-useragent: 
            # Used https://core.telegram.org/bots/samples for this list
            - '*Telegram*'
            - '*Bot*'
    condition: selection and not filter
fields:
    - ClientIP
    - c-uri
    - c-useragent
falsepositives:
    - Legitimate use of Telegram bots in the company
level: medium
tags:
    - attack.defense_evasion
    - attack.command_and_control
    - attack.t1071.001
    - attack.t1043  # an old one
    - attack.t1102.002
    - attack.t1102  # an old one