Bugku CTF daily one question dark cloud invitation code

Black cloud invitation code

Open and find a picture , use winhex Open and find many different places from ordinary pictures
No exceptions were found when opening the properties
But in STEGSLOVE Opened but found an exception ,RGB All in 0 Bit has an exception as shown in the following figure

So consider RGB Steganography , however RGB No useful information , But make it BGR It shows flag

Mysterious documents

Open and find two files , But after careful observation, we can find that the unencrypted file outside is encrypted zip Files also have files of the same name , So we can consider plaintext attack , But to be sure, it still depends on CRC32 Are they the same? （ This one uses winrar You can see ）
Then compress the outside picture （ Here want to use winrar, Use others such as 360 Compression causes ARCHPR Prompt that there is no matching file in the selected file ）
And then put two files in it , Select the plaintext attack

Get the password and open it to get a docx file , use winhex Open discovery PK Prefix , It should be a compressed package , Open it and find... In its directory flag.txt, And then use base64 Decrypt to get flag