Challenge Description#

johnbuck69420 believes he is a big consipiracy theorist. His recent ramblings have been about a strange artist whose works supposedly predict the future. Most people think he’s crazy but John insists otherwise. He believes that the artist is warning us about a new disease.

Analysis#

This one was a clean OSINT chain once the description was taken literally. The clue johnbuck69420 looked like a direct username, so I started by dorking that handle and found the matching X/Twitter account shown below.

After opening that account, the posts clearly revolved around conspiracy themes and a mysterious artist supposedly predicting future events, which matched the challenge narrative and confirmed this was the right pivot point.

From those posts, I identified the referenced Instagram username and used it as the next hop in the OSINT chain.

On that Instagram profile, the artist identity appears as blessonlal, which gives the first required flag component (the artist name).

Reviewing the feed confirmed this was the same artwork thread being discussed by John, so the context link between X/Twitter and Instagram was solid.

Then the relevant post captioned black iris gave the second component. The challenge says the artist is warning about a new disease, and the image reads as a COVID-style lung-disease warning (damaged lungs visualized through black-iris flowers). In other words, the disease context points to COVID, but the concrete token provided by the post itself is black iris, so the flag uses the normalized form blackiris. Combining both extracted parts under the given format apoorvctf{artist'sName_diseaseName} yields apoorvctf{blessonlal_blackiris}.

Solution#

Use the username clue as the entry point, pivot from John’s X/Twitter posts to the referenced artist Instagram profile, then extract the two required tokens from the screenshots:

• artist name: blessonlal
• disease name token from caption: blackiris

apoorvctf{blessonlal_blackiris}