The Hammers rejected a loan bid from Marseille earlier this week, on the same day that Benrahma was shown the first red card of his career during the FA Cup exit at Bristol City.
Fellow French side Lyon are also understood to be interested in the Algerian, whose three-match suspension means he may well have played his final game for the Hammers.
“I do believe Marseille made a loan offer,” Moyes said on Friday, ahead of the weekend’s trip to Sheffield United. “I didn’t know about it after the [Bristol City] game. As far as I know, it was knocked back anyway.
"We probably need to sell to get some other players in. If that’s the case then we’re probably in a selling mood, rather than a loaning mood.”
West Ham have already allowed Thilo Kehrer to move to Ligue 1 on loan this month, though that deal is thought to include an obligation to make the switch permanent in the summer.
Asked whether more players would be sold before the window closes, Moyes said: “The truth is it’s probably 50/50. I’ve got no absolute definitive saying somebody else is going but yeah, there's noises in the background that maybe some other people may go.
“We probably wanted some outs before we had people coming in. I said our budget isn't huge in this window. There's lots of reasons why there's probably not a lot of signings going on.”
As well as Benrahma, the club were initially open to offers for Pablo Fornals, Maxwel Cornet and Danny Ings this month, but a host of attacking injuries have forced Moyes into using those players in his first-team in recent weeks.
The Hammers remain in the market for a wide player and are also hoping to revive long-standing interest in Kalvin Phillips, who is likely to leave Manchester City on loan.
“We’d like to strengthen all-round,” Moyes added. “If we could sign somebody in a couple of areas we would try and do so but there’s no specific.
“The bigger problem at the moment is we’ve lost Mo [Kudus], got an injury with Jarrod [Bowen] and Lucas [Paqueta] so a lot of things changed. Maybe our thoughts were different two weeks ago to what they are now. It’s moving all the time on where we think we might need to add players.”