Pdf-jpgs

Hi guys. Can everyone help me:

Two images that look completely ordinary are pasted in the PDF file, and it is highly unlikely that these files are normal.
find a flag in PDF file.

flag format:flag{[A-Za-z_]}

File:

https://ctf.laocert.la/download?file_key=2ae22faf6141dcd80543c3b183a5c6b453294ad49726507f2c8bc20919ed4ebf&team_key=dd89c8b4f94a963a02b496fec932dbb83ecc66561284a4906fd9c8fdc3fcaf46