Attila isn't viewed as a national hero, that would imply he is seen as a national and he is not. He isn't represented on Heroes Square, and I'm not aware of any Attila memorials in the country either. That said he does have a significance in historical memory and in legends, as a kind of a precessedor figure to Hungarians. This stems from medieval legends which sought to ascribe greater legacy to early Hungarian kings, both for prestige and to strengthen their claim to the land and throne. These legends were recorded in several works, notably in the Gesta Hungarorum by Anonymous and Simon de Kéza's work Gesta Hunnorum et Hungarorum. While Anonymous doesn't go great lengths in this regard and just ascertains that Attila is the ancestor of the early Hungarian leaders, and that the name Hungarian derives from Hunnic (a false etymology by the way). Kéza as his work implies goes much beyond and its classically him where the medieval tradition of accepting a hunnic-hungarian connection is dated to start. One particular legend recorded in several works is that of Hunor and Magor, sons of either Magog of Menrot, King of Scythians. Both were hunters whom in search of the mythical white stag arrived to a rich land called Meotis, where they settled, multiplied and eventually moved out and parted ways. Hunor is the ancestors of Huns and Magor of Magyars-Hungarians in the story.

However the whole matter is not so clear as due to the several centuries between Hungarians and Huns its not thought that direct legends survived, instead Hungarians may have adopted it from the Onogurs. Further issue is that Constantine VII mentions a certain Attila as "King of Avars", meaning its likely the name survived as a kind of title among steppe people, making identification of the legends Attila and Hunor with the actual Attila and Hunnic peoples less than certain, and since theres a general lack of records on early Hungarian history historians can't reach a verdict. Also foreign works could have influenced the chronicles too, Kéza himself states he worked based on French, Italian and German papers.

Whatever did early Hungarians actually believe, nonethelles thanks to medieval chroniclers the tradition of hunnic ancestry became accepted among the leading ranks of the kingdom, with the kings tracing themselves to Attila and the noble dynasties to various Hunnic genuses. István Werbőczy, a prominent chief justice extols the Hungarian nobility through their Hunnic ancestry in his 1514 Tripartitum. György Pray's 1774 Dissertationes Historico-Criticæ In Annales Veteres Hunnorum, Avarum et Hungarorum is seen as the first critical work looking into the history of Huns, Avars and Hungarians.

However starting with Hunfalvy's work in the early 19. century the Finno-Ugric hypothesis slowly took over the Turkic-Hunnic origin idea, and by the late 19. century it was no longer considered a scientific theory. Also if it wasn't obvious yet the Hunnic origin story never concerned the entire society but the upper classes who they used it to extend their prestige and pedigree. Now public consciousness takes longer times to change and some fascination with Attila and the Huns is still present in Hungary, still except marginal minorities he is no longer seen as an ancestor to Hungarians.