As other commenters noted, this is almost certainly not RF spoofing, just sending bad data to an aggregator (ADS-B Exchange) over the internet.

This instance of spoofing is notable for being the first that I know of that wasn't primitive vector art or text, but a raster image!

In that area of Florida multiple receivers would have picked up actual ADS-B broadcasts. ADS-B aggregators do have various anti-spoofing measures, but they're not impossible to circumvent.

The only case of actual RF spoofing of aircraft transponder signals that I know of was actually done by the U.S. Secret Service, which interfered with passenger jet collision alert systems (TCAS) by apparently broadcasting bogus signals near Ronald Reagan National Airport (KDCA): https://nymag.com/intelligencer/article/aviation-flights-whi...

Just because I don't often get a chance to talk about this, I'll mention that there was a malfunction/accident/bug that caused what you might call spoofed signals to go out around Long Island and New York. Really interesting case where it seems that an FAA system wasn't handling magnetic declination correctly, which led to it generating false TIS-B targets that were rotated 13 degrees from real aircraft positions, from the radar antenna point of view: https://x.com/lemonodor/status/1508505542423064578

(TIS-B is a system that broadcasts ADS-B-like signals for aircraft that are being tracked by radar but either don't have ADS-B Out or otherwise might not be picked up by other aircraft with ADS-B In, e.g. maybe they're at a low altitude.)

There have been a couple other incidents with the TIS-B system. E.g. this apparent test near Dallas in 2022 that generated dozens of false targets in an interesting pattern: https://x.com/lemonodor/status/1481712428932997122 There was a similar incident around LAX several months later.

I agree with this. Hopefully they're able to track down who did this. To upload to ADS-B Exchange you need an account. But it's not that difficult to get one. I'm not sure what kind of information they may be able to get on it. As you say the person who uploaded this may not be anywhere near there. The aggregators probably should have heuristics like if only one feeder in an area with a decent density of feeder coverage uploads an anomalous track, it should get flagged.

Notably, the history of this aircraft shows MLAT as the source for all tracking. This spoof is the first ads-b “track” for this plane.

But there’s so much wrong with the data: 50k ft at 80knots (ground speed!) in a 747.

(Of course if you were spoofing ADS-B RF signals you wouldn't necessarily need to be anywhere near the spoofed locations. Just like with GPS spoofing.)