I think it’s legit:
❯ codesign -dvvv /Volumes/ChatGPT\ Installer/ChatGPT.app
Executable=/Volumes/ChatGPT Installer/ChatGPT.app/Contents/MacOS/ChatGPT
Identifier=com.openai.chat
Format=app bundle with Mach-O thin (arm64)
CodeDirectory v=20500 size=2011 flags=0x10000(runtime) hashes=52+7 location=embedded
Hash type=sha256 size=32
CandidateCDHash sha256=9eade7e29659107c048f766219642f6be9a2788d
CandidateCDHashFull sha256=9eade7e29659107c048f766219642f6be9a2788d9ccda47e1b83e23195e63af9
Hash choices=sha256
CMSDigest=9eade7e29659107c048f766219642f6be9a2788d9ccda47e1b83e23195e63af9
CMSDigestType=2
CDHash=9eade7e29659107c048f766219642f6be9a2788d
Signature size=9047
Authority=Developer ID Application: OpenAI, L.L.C. (2DC432GLL2)
Authority=Developer ID Certification Authority
Authority=Apple Root CA
Timestamp=May 14, 2024 at 5:53:18 AM
Info.plist entries=39
TeamIdentifier=2DC432GLL2
Runtime Version=14.2.0
Sealed Resources version=2 rules=13 files=3191
Internal requirements count=1 size=208
Same as TeamIdentifier comparing to ChatGPT iOS App
❯ codesign -dvvv /Users/hewig/Downloads/com.openai.chat_6448311069_1.2024.122/Payload/ChatGPT.app
Executable=/Users/hewig/Downloads/com.openai.chat_6448311069_1.2024.122/Payload/ChatGPT.app/ChatGPT
Identifier=com.openai.chat
Format=app bundle with Mach-O thin (arm64)
CodeDirectory v=20500 size=2907 flags=0x0(none) hashes=40+7 location=embedded
Hash type=sha256 size=32
CandidateCDHash sha1=6ed97aca42166f4f34376d76766fb74fcf3b0d82
CandidateCDHashFull sha1=6ed97aca42166f4f34376d76766fb74fcf3b0d82
CandidateCDHash sha256=5c2ea78c2139bae82d2da39e6cf816b89735d7a2
CandidateCDHashFull sha256=5c2ea78c2139bae82d2da39e6cf816b89735d7a23833eddb5c49365dee6eac00
Hash choices=sha1,sha256
CMSDigest=2fdeda6b1b50699413be8449e0014efb90937d9cd1918ab8bc57d8857b970314
CMSDigestType=2
CDHash=5c2ea78c2139bae82d2da39e6cf816b89735d7a2
Signature size=4384
Authority=Apple iPhone OS Application Signing
Authority=Apple iPhone Certification Authority
Authority=Apple Root CA
Info.plist entries=44
TeamIdentifier=2DC432GLL2
Sealed Resources version=2 rules=18 files=365
Internal requirements count=1 size=96