<b_jonas> ` f=bin/w\xc3\xa4lc\xc3\xa5m\xc3\xa4; >"$f" echo $\'/bin/sh\\nwelcome | sed "s/E/\xc3\x84/g;s/O/\xc3\x85/g;s/e/\xc3\xa4/g;s/o/\xc3\xa5/g"\'; chmod a+x "$f"

Complaints file lacks file extension making it look like a directory. Which is confusing