Ann, a security analyst, has been notified that trade secrets are being leaked from one of the executives in the corporation. When reviewing this executive's laptop she notices several pictures of…

Social engineering involves manipulating people through deception or psychological tactics to gain information or access, and does not describe the technical method of embedding data in image files.

Steganography conceals information within a carrier file - in this case, images of pets - so that the existence of the hidden message is not obvious. The fact that the MD5/hash values of the images on the hard drive do not match those on the cloud network proves the files were altered, which is consistent with secret data being embedded in the images. This technique allows the executive to exfiltrate trade secrets while the files appear to be ordinary personal photos.

Hashing is the method Ann used to detect that the images were different - it is a detection technique, not the method of leaking data.

Digital signatures are used to verify the authenticity and integrity of a message or file and are not a technique for hiding or exfiltrating secret data.