Can someone help me identify this spider?
According to museum.wa.gov.au, there are four solifugid species in Malawi. Ceroma johnstonii, Ceroma zomba, Zeria niassa and Zeria paludicola.

Ceroma johnstonii has a grayish-brown tint, not the dark brown, almost black coloration (and red) of your solifugid. Ceroma zomba is only 8 mm in length, much too small even if your estimate of 50-60 mm was referring to the legspan.

Zeria niassa is only 24-28 mm in body length, significantly smaller than what you saw unless you meant legspan. Zeria paludicola is also smaller than your 50-60 mm estimate, so it must have been the legspan, not the length. The only photo I could find of any Zeria species is from eol.org and is of an unspecified species. In the photo, it has a dark brown coloration and a very faint tinge of red on the side of the abdomen.



So your image is either of Zeria niassa or Zeria paludicola.