## SolutionCyberChef can be used to base64 decode the string, then BSON deserialize the result:![](https://malcrypt.gitlab.io/blog/ctfs/2021/tenable/images/not_json/cyber_chef.png)
The result is a string, and a list of integers. Use the list of integers as indexes into the string to get the flag:```python>>> indexes = [5,11,0,6,27,18,14,13,26,14,5,26,0,26,1,18,14,13,28]>>> s = "abcdefghjiklmnopqrstuvwxyz_{}">>> flag = "">>> for i in indexes:...     flag += s[i]...>>> print(flag)flag{son_of_a_bson}```
## Flag**flag{son_of_a_bson}**