Final answer:
Kaposi's sarcoma is the malignancy of connective tissue closely associated with AIDS, presenting as red raised skin lesions and is the most common cancer in people with AIDS.
Step-by-step explanation:
The malignancy of connective tissue closely associated with AIDS is Kaposi's sarcoma. This type of cancer originates from the cells that line the blood and lymphatic vessels. Kaposi's sarcoma is the most common type of opportunistic cancer in people with AIDS, presenting as red raised scab-like skin lesions and occurring in 10 to 20 percent of AIDS patients. It is associated with the human herpesvirus 8 (HHV-8), a virus that typically does not cause illness in individuals with a healthy immune system. Due to the immune system dysfunction caused by HIV, people with AIDS are at an increased risk of developing several malignancies, including this particular sarcoma.