If that’s what they spliced it with, it was wired for phone and probably won’t work for ethernet. It’s possible to run 10Mbps ethernet over ancient cat3 wiring, but it still needs to be connected properly. If all four outlets meet in one spot, they can just be wired together for phone but would need a switch for ethernet. And you typically don’t want to have the switch up in the attic.
If feasible, I’d rip it out and replace with modern stuff (Cat6a or thereabouts), routing all the outlets to somewhere a switch can reasonably be located. If the wiring is cat 5 or better it would probably work if you replaced any such joints with a proper “network” one (may not do gigabit, but probably 100Mbit), but it would still be kinda iffy.
If the 1-8 markings correspond to pin numbers in the socket, it’s neither, and also not a suitable wiring for ethernet. It might “kinda work”, but probably not very well and it’s definitely not proper. The pairs should be 1-2, 3-6, 4-5 and 7-8. Color really doesn’t matter much as long as it’s the same at both ends (with TIA568A/B being the two most popular way of arranging the colors). That one is neither, with the pairs being 1-2, 3-4, 5-6, 7-8.
As widely suggested by others, remove those jacks and replace with non-silly stuff (at both ends). TIA568B seems to be the most popular one to use, but as long as you follow the same standard everywhere (anything else will be gravely confusing) it’ll work.