Infectious Rage — ruling 1

When this card returns to the battlefield, it is put onto the battlefield on the creature without targeting it, so it can be placed on a creature with Shroud.

Infectious Rage — ruling 2

You can't return this card to the battlefield onto something it can't enchant. For example, you can't place this card on a permanent with protection from red.

Infectious Rage : règles, fonctionnement et interactions (MTG)

Infectious Rage is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Enchant creature Enchanted creature gets +2/-1. When enchanted creature dies, choose a creature at random this Aura can enchant. Return this card to the battlefield attached to that creature.

How it works : Infectious Rage

Original English text — Wizards of the Coast / Scryfall

#1October 4, 2004· Wizards of the Coast
When this card returns to the battlefield, it is put onto the battlefield on the creature without targeting it, so it can be placed on a creature with Shroud.
No other card is named in this ruling.
#2October 4, 2004· Wizards of the Coast
You can't return this card to the battlefield onto something it can't enchant. For example, you can't place this card on a permanent with protection from red.
No other card is named in this ruling.