For Lectures_22_Forensics challenge,I opened the pdf first scrolling all the way down till 19 pages there was nothing interesting found in the pdf. But when I search for string such as  ```wsc{``` I found some interesting content across page 17th. So I simply googled pdf data extractor tool online and I found the following link : [https://www.pdf-online.com/osa/extract.aspx](https://www.pdf-online.com/osa/extract.aspx) . So after that I uploaded the file on that website and set the page number to 17 and I finally got the flag there in the Raw PDF Fragments. 
Flag for Lectures_22_Forensics :``` wsc{y0u_c4nT_$ee_m3}```