If anyone doesn't want to mess with their code, I made a patch.
Cág
diff --git a/dwm.c b/dwm.c
index 421bf27..26ef7bf 100644
--- a/dwm.c
+++ b/dwm.c
@@ -1580,7 +1580,7 @@ setup(void)
netatom[NetClientList] = XInternAtom(dpy, "_NET_CLIENT_LIST", False);
/* init cursors */
cursor[CurNormal] = drw_cur_create(drw, XC_left_ptr);
- cursor[CurResize] = drw_cur_create(drw, XC_sizing);
+ cursor[CurResize] = drw_cur_create(drw, XC_bottom_right_corner);
cursor[CurMove] = drw_cur_create(drw, XC_fleur);
/* init appearance */
scheme[SchemeNorm] = drw_scm_create(drw, colors[SchemeNorm], 3);