La réponse :

# cat /etc/iptables/rules.v4 | grep "DROP" | awk '{print $4}' | sed 's/\// /g' | awk '{print $1}' | xargs -n 1 geoiplookup { } | sort | uniq -c | sort -n | sed -r 's/ GeoIP Country Edition://g'
      1 AL, Albania
      1 AT, Austria
      1 CZ, Czech Republic
      1 GR, Greece
      1 IE, Ireland
      1 JP, Japan
      1 PH, Philippines
      1 TT, Trinidad and Tobago
      1 UG, Uganda
      2 ID, Indonesia
      2 IR, Iran, Islamic Republic of
      2 IT, Italy
      2 MX, Mexico
      2 MY, Malaysia
      2 SG, Singapore
      2 TR, Turkey
      2 TW, Taiwan
      3 BR, Brazil
      3 SC, Seychelles
      3 VN, Vietnam
      4 DE, Germany
      4 EG, Egypt
      4 GB, United Kingdom
      5 FR, France
      5 KR, Korea, Republic of
      6 CA, Canada
      6 RU, Russian Federation
      7 NL, Netherlands
     11 IN, India
     15 IP Address not found
     38 CN, China
     90 US, United States

Mon OS :

# cat /etc/os-release 
PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"