Well, I just found a guide on how to install twrp 3.2.3 on a Samsung Galaxy Star here, which has the model number SM-J337T. It has the exact same SoC, CPU and GPU as my device. The guide has a link to an unnoficial twrp recovery.img image. Would it be safe for me to use that for my SM-J337W?
PS. What does the T and W mean in the device model number?
Well, they say that development for these phones is mostly dead.
Also, I do think that getting a virus by simply downloading Android ROMs from some unknown source (or an open source project maintained only by 1 person) would be quite easy. Not to mention that xz-utils, an open-source project was recently backdoor-ed.