Compromise Host Software Binary

WARPWIRE can embed itself into a legitimate file on compromised Ivanti Connect Secure VPNs.(Citation: Mandiant Cutting Edge January 2024)

Industroyer has used a Trojanized version of the Windows Notepad application for an additional backdoor persistence mechanism.(Citation: ESET Industroyer)

BFG Agonizer uses DLL unhooking to remove user mode inline hooks that security solutions often implement. BFG Agonizer also uses IAT unhooking to remove user-mode IAT hooks that security solutions also use.(Citation: Unit42 Agrius 2023)

During Cutting Edge, threat actors trojanized legitimate files in Ivanti Connect Secure appliances with malicious code.(Citation: Mandiant Cutting Edge January 2024)(Citation: Volexity Ivanti Zero-Day Exploitation January 2024)(Citation: Mandiant Cutting Edge Part 2 January 2024)

BUSHWALK can embed into the legitimate `querymanifest.cgi` file on compromised Ivanti Connect Secure VPNs.(Citation: Mandiant Cutting Edge Part 2 January 2024)(Citation: Mandiant Cutting Edge Part 3 February 2024)

Kobalos replaced the SSH client with a trojanized SSH client to steal credentials on compromised systems.(Citation: ESET Kobalos Jan 2021)

APT5 has modified legitimate binaries and scripts for Pulse Secure VPNs including the legitimate DSUpgrade.pm file to install the ATRIUM webshell for persistence.(Citation: Mandiant Pulse Secure Zero-Day April 2021)(Citation: Mandiant Pulse Secure Update May 2021)

Kessel has maliciously altered the OpenSSH binary on targeted systems to create a backdoor.(Citation: ESET ForSSHe December 2018)

ThiefQuest searches through the /Users/ folder looking for executable files. For each executable, ThiefQuest prepends a copy of itself to the beginning of the file. When the file is executed, the ThiefQuest code is executed first. ThiefQuest creates a hidden file, copies the original target executable to the file, then executes the new hidden file to maintain the appearance of normal behavior. (Citation: wardle evilquest partii)(Citation: reed thiefquest ransomware analysis)

LITTLELAMB.WOOLTEA can append malicious components to the `tmp/tmpmnt/bin/samba_upgrade.tar` archive inside the factory reset partition in attempt to persist post reset.(Citation: Mandiant Cutting Edge Part 3 February 2024)

BOLDMOVE contains a watchdog-like feature that monitors a particular file for modification. If modification is detected, the legitimate file is backed up and replaced with a trojanized file to allow for persistence through likely system upgrades.(Citation: Google Cloud BOLDMOVE 2023)

Ebury modifies the `keyutils` library to add malicious behavior to the OpenSSH client and the curl library.(Citation: ESET Ebury Feb 2014)(Citation: ESET Ebury May 2024)

LIGHTWIRE can imbed itself into the legitimate `compcheckresult.cgi` component of Ivanti Connect Secure VPNs to enable command execution.(Citation: Mandiant Cutting Edge January 2024)(Citation: Mandiant Cutting Edge Part 2 January 2024)

Bonadan has maliciously altered the OpenSSH binary on targeted systems to create a backdoor.(Citation: ESET ForSSHe December 2018)

XCSSET uses a malicious browser application to replace the legitimate browser in order to continuously capture credentials, monitor web traffic, and download additional modules.(Citation: trendmicro xcsset xcode project 2020)

During the 2016 Ukraine Electric Power Attack, Sandworm Team used a trojanized version of Windows Notepad to add a layer of persistence for Industroyer.(Citation: ESET Industroyer)

FRAMESTING can embed itself in the CAV Python package of an Ivanti Connect Secure VPN located in `/home/venv3/lib/python3.6/site-packages/cav-0.1-py3.6.egg/cav/api/resources/category.py.`(Citation: Mandiant Cutting Edge Part 2 January 2024)

SLOWPULSE is applied in compromised environments through modifications to legitimate Pulse Secure files.(Citation: Mandiant Pulse Secure Update May 2021)

WIREFIRE can modify the `visits.py` component of Ivanti Connect Secure VPNs for file download and arbitrary command execution.(Citation: Mandiant Cutting Edge January 2024)(Citation: Volexity Ivanti Zero-Day Exploitation January 2024)

Code Signing is a security process that ensures the authenticity and integrity of software by digitally signing executables, scripts, and other code artifacts. It prevents untrusted or malicious code from executing by verifying the digital signatures against trusted sources. Code signing protects against tampering, impersonation, and distribution of unauthorized or malicious software, forming a critical defense against supply chain and software exploitation attacks. This mitigation can be implemented through the following measures: Enforce Signed Code Execution: - Implementation: Configure operating systems (e.g., Windows with AppLocker or Linux with Secure Boot) to allow only signed code to execute. - Use Case: Prevent the execution of malicious PowerShell scripts by requiring all scripts to be signed with a trusted certificate. Vendor-Signed Driver Enforcement: - Implementation: Enable kernel-mode code signing to ensure that only drivers signed by trusted vendors can be loaded. - Use Case: A malicious driver attempting to modify system memory fails to load because it lacks a valid signature. Certificate Revocation Management: - Implementation: Use Online Certificate Status Protocol (OCSP) or Certificate Revocation Lists (CRLs) to block certificates associated with compromised or deprecated code. - Use Case: A compromised certificate used to sign a malicious update is revoked, preventing further execution of the software. Third-Party Software Verification: - Implementation: Require software from external vendors to be signed with valid certificates before deployment. - Use Case: An organization only deploys signed and verified third-party software to prevent supply chain attacks. Script Integrity in CI/CD Pipelines: - Implementation: Integrate code signing into CI/CD pipelines to sign and verify code artifacts before production release. - Use Case: A software company ensures that all production builds are signed, preventing tampered builds from reaching customers. **Key Components of Code Signing** - Digital Signature Verification: Verifies the authenticity of code by ensuring it was signed by a trusted entity. - Certificate Management: Uses Public Key Infrastructure (PKI) to manage signing certificates and revocation lists. - Enforced Policy for Unsigned Code: Prevents the execution of unsigned or untrusted binaries and scripts. - Hash Integrity Check: Confirms that code has not been altered since signing by comparing cryptographic hashes.