Sigma rule: Suspicious Non-Browser Network Communication With Telegram API

Rule

Title

Suspicious Non-Browser Network Communication With Telegram API

Status

test

Level

medium

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2023-05-19

File

rules/windows/network_connection/net_connection_win_domain_telegram_api_non_browser_access.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects an a non-browser process interacting with the Telegram API which could indicate use of a covert C2

Log source

product

windows

category

network_connection

Detection

selection:
    DestinationHostname|contains: 'api.telegram.org'
# Other browsers or apps known to use telegram should be added
# TODO: Add full paths for default install locations
filter_main_brave:
    Image|endswith: '\brave.exe'
filter_main_chrome:
    Image:
        - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
        - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
filter_main_firefox:
    Image:
        - 'C:\Program Files\Mozilla Firefox\firefox.exe'
        - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
filter_main_ie:
    Image:
        - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
        - 'C:\Program Files\Internet Explorer\iexplore.exe'
filter_main_maxthon:
    Image|endswith: '\maxthon.exe'
filter_main_edge_1:
    - Image|startswith: 'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\'
    - Image|endswith: '\WindowsApps\MicrosoftEdge.exe'
    - Image:
          - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
          - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
filter_main_edge_2:
    Image|startswith:
        - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
        - 'C:\Program Files\Microsoft\EdgeCore\'
    Image|endswith:
        - '\msedge.exe'
        - '\msedgewebview2.exe'
filter_main_opera:
    Image|endswith: '\opera.exe'
filter_main_safari:
    Image|endswith: '\safari.exe'
filter_main_seamonkey:
    Image|endswith: '\seamonkey.exe'
filter_main_vivaldi:
    Image|endswith: '\vivaldi.exe'
filter_main_whale:
    Image|endswith: '\whale.exe'
condition: selection and not 1 of filter_main_*

False positives (as the rule lists them)

• Legitimate applications communicating with the Telegram API e.g. web browsers not in the exclusion list, app with an RSS etc.

Tags

• attack.command-and-control
• attack.exfiltration
• attack.t1102
• attack.t1567
• attack.t1105

MITRE ATT&CK ids this rule names

• T1102
• T1105
• T1567

References

• https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/small-sieve/NCSC-MAR-Small-Sieve.pdf

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/network_connection/net_connection_win_domain_telegram_api_non_browser_access.yml