Writeup for the IOException recon problem in EasyCTF 2015 by µ’s
By googling "ioexception michael zhang" and "ioexception osu", we find:
The MuseScore profile leads us to a blog on WordPress.com.
Upon examining the picture in the header of the website, we discover that its filename is ioexception_recon.png.
If we examine this file with a tool to read EXIF data such as Jeffrey's Exif Viewer,
we discover part 1 embedded in the picture as an EXIF comment.
part 1: easyctf{yeee3ee3ew_
Next, we look at the only sheet music available on the MuseScore account, Spirit Tracks - Realm Overworld. Clicking to the final page, we find part 2 located at the bottom.
part 2: sha44aal11l1l1l_
Then, we return to the osu! account, and by scrolling to the bottom of the account description near the top of the page, we find part 3.
For people playing EasyCTF 2015, the 3rd part of the flag for IOException's recon problem is bE#eeee_.
Finally, we look at failedxyz's gists, sorting by recently updated. We find chokes.md, which has something to do with IOException, and by examining the revisions tab we find part 4.
Part 4 for IOException recon is: azzzzzsimmileitted!!}
It's a bit difficult to determine whether part 2 contains lowercase L's or uppercase i's, which cannot easily be distinguished. But by looking at the flag as a whole, we realize that it appears to be the Anomalous Materials slogan "You shall be assimilated", so the letters must be L's. The flag is then:
easyctf{yeee3ee3ew_sha44aal11l1l1l_bE#eeee_azzzzzsimmileitted!!}