Tainted Strike (SOM) from Scars of Mirrodin, available at 401 Games Canada.

• Rarity: Common
• Finish: Normal
• Artist: James Ryman
• Card Text:
  Target creature gets +1/+0 and gains infect until end of turn. (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)