Thanks for your answer! The reason I asked is that I did not have the source code, and upon request CommerceTools apparently does not disclose the algorithm for "security reasons".
However, I suspected it was written in Java, and just found this Stack Overflow post which uses the same format.
From there, it was just an easy search through all Java algorithms and configurations (the code is O(n²) to iteration sizes and not parallelized, let alone GPU, but that didn't matter).
Turns out, the first half is the salt, and the second half is PBKDF2 with HMAC construction, SHA1, and 4096 iterations.
However, I suspected it was written in Java, and just found this Stack Overflow post which uses the same format.
From there, it was just an easy search through all Java algorithms and configurations (the code is O(n²) to iteration sizes and not parallelized, let alone GPU, but that didn't matter).
Turns out, the first half is the salt, and the second half is PBKDF2 with HMAC construction, SHA1, and 4096 iterations.