So Vikings were from Denmark at the time, and in present day territories that overlap Denmark, Sweden and Norway. Kievan Rus were eastern slavs and eventually also Finnic peoples or "Varangians".
There is some debate as to whether or not Varangians from Finland are considered Vikings to this day...
"Controversy persists over whether the
Rus' were
Varangians (Vikings) or Slavs. This uncertainty is due largely to a paucity of contemporary sources. Attempts to address this question instead rely on archaeological evidence, the accounts of foreign observers, and legends and literature from centuries later.
[24] To some extent the controversy is related to the
foundation myths of modern states in the region.
[25] According to the "
Normanist" view, the Rus' were Scandinavians, while Russian and Ukrainian nationalist historians generally argue that the Rus' were themselves Slavs.
[26][27][28] Normanist theories focus on the earliest written source for the
East Slavs, the
Primary Chronicle,
[29] although even this account was not produced until the 12th century.
[30] Nationalist accounts have suggested that the Rus' were present before the arrival of the Varangians,
[31] noting that only a handful of Scandinavian words can be found in
modern Russian and that Scandinavian names in the early chronicles were soon replaced by Slavic names.
[32] Nevertheless, archaeological evidence from the area suggests that a Scandinavian population was present during the 10th century at the latest.
[33] On balance, it seems likely that the Rus' proper were a small minority of Scandinavians who formed an elite ruling class, while the great majority of their subjects were Slavs.
[32] Considering the linguistic arguments mounted by nationalist scholars, if the proto-Rus' were Scandinavians, they must have quickly become
nativized, adopting Slavic languages and other cultural practices."
en.wikipedia.org
That's pretty neat, I had no idea that a controversy even existed. I'll concede that what I wrote is not entirety accurate but equally so was your claim about them.