MOSCOW — The gunman who attacked the headquarters of Russia’s feared security agency this week and killed one of its agents was an unemployed security guard and gun enthusiast, various Russian news outlets reported on Friday.

The gunman, identified as Yevgeny F. Manyurov, 39, wounded five other people before being killed by the police in the assault, which took place on Thursday, the authorities said.

While official sources of information have been largely silent, many Russian news outlets and social media accounts known for having connections with the security services have filled the vacuum.

He was widely described in the Russian news media as a loner who lived with his mother.

Ren-TV, a Russian news network, said that Mr. Manyurov lived in Podolsk, Russia, just south of Moscow, and that he enjoyed practice shooting in his free time and did not have many friends. The news network also published a picture of the gunman shortly after he was killed, showing what appeared to be a heavyset man with a full beard.