Table updation by some other user name

Hi,

In Invoice workflow, when changing from one status to another status, updating custom table with OCR details.

User A has changed the status and same is reflecting in workflow log but in custom table user B name got updated.

User B is not in office at all, and no where related to this workflow execution.

I need to know how user B name is updated in custom table. I have checked the workflow log user B name not showing anywhere, and other programs also not got executed to update the custom table. I have also checked the substitutions for the users in HRUS_D2 table. But substitution not maintained.

Please help me in this.

Thanks & Regards,

Priya