I'm pretty sure that your question is not related to Security Advisory = VMSA-2021, in which forum you posted it.
Please let me know which VMware product, and version you are using, and provide some more information, like the .vmdk file's file format. In doubt, extract the first 1536 Bytes, and post them here.
Get-Content "filename.vmdk" -Encoding Byte -TotalCount 1536 | Format-Hex
André