## 1. `zsteg`

┌──(kali㉿kali)-[~/code/for]
└─$ zsteg -s first buildings.png
b1,r,lsb,xy         .. text: "^5>R5YZrG"
b1,rgb,lsb,xy       .. text: "picoCTF{h1d1ng_1n_th3_b1t5}"
b1,abgr,msb,xy      .. file: PGP Secret Sub-key -
b2,b,lsb,xy         .. text: "XuH}p#8Iy="
b3,abgr,msb,xy      .. text: "t@Wp-_tH_v\r"
b4,r,lsb,xy         .. text: "fdD\"\"\"\" "
b4,r,msb,xy         .. text: "%Q#gpSv0c05"
b4,g,lsb,xy         .. text: "fDfffDD\"\""
b4,g,msb,xy         .. text: "f\"fff\"\"DD"
b4,b,lsb,xy         .. text: "\"$BDDDDf"
b4,b,msb,xy         .. text: "wwBDDDfUU53w"
b4,rgb,msb,xy       .. text: "dUcv%F#A`"
b4,bgr,msb,xy       .. text: " V\"c7Ga4"
b4,abgr,msb,xy      .. text: "gOC_$_@o"

## 2. online decoder
As mentioned in Hint, use an [online decoder](https://stylesuxx.github.io/steganography/) to decode the image