The answer is Staphylococcus aureus.
Boil (furuncle) presents skin infections, usually associated with infections near the root of the hair or the sebaceous gland. The most common causative agent of boils is Staphylococcus aureus, a penicillin-resistant bacteria. It is formed by pushing the bacteria in one place in the skin, which results in the creation of pus. A boil is most often the result of insufficient skin hygiene (if the skin is unevenly cleaned), then accidental and invisible damage that is not treated in a timely manner.