Code signatures on Windows executables provide guarantees about the integrity of a signed executable, as well as information about the identity of the signer.
Attackers who are able to obscure their identity in signatures without affecting the integrity of the signature can avoid detection longer and extend the lifetime of their code-signing certificates to infect more systems.
OpenSUpdater, a known family of unwanted software which violates our policies and is harmful to the user experience, is used to download and install other suspicious programs.
The actor behind OpenSUpdater tries to infect as many users as possible and while they do not have specific targeting, most targets appear to be within the United States and prone to downloading game cracks and grey-area software.
Groups of OpenSUpdater samples are often signed with the same code-signing certificate, obtained from a legitimate certificate authority.
Since mid-August, OpenSUpdater samples have carried an invalid signature, and further investigation showed this was a deliberate attempt to evade detection.
In these new samples, the signature was edited such that an End of Content (EOC) marker replaced a NULL tag for the ‘parameters’ element of the SignatureAlgorithm signing the leaf X.509 certificate.
EOC markers terminate indefinite-length encodings, but in this case an EOC is used within a definite-length encoding (l= 13).
Sign Up For Threat Alerts
Jul 04, 2023
Rhysida Ransomware RaaS Crawls Out of Crimeware...
The Rhysida ransomware-as-a-service (RaaS) group has gone from a dubious newcomer to a fully-fledged ransomware...
Jun 26, 2023
Operation Magalenha – Long-Running Campaign Pursues Portuguese...
The attackers can steal credentials and exfiltrate users' data and personal information, which can be...
Apr 24, 2023
Lazarus Group Adds Linux Malware to Arsenal...
Researchers have discovered a new campaign conducted by Lazarus, known as "Operation DreamJob," which targets...
Apr 23, 2023
Additional IOCs for 3cx breach
Recently an unexpected malicious activity emanating from a legitimate, signed binary, 3CXDesktopApp was observed.
Apr 23, 2023
Ex-Conti and FIN7 Actors Collaborate with New...
IBM Security X-Force recently discovered a new malware family Analysts have called "Domino," which Analysts...
Apr 20, 2023
AuKill EDR killer malware abuses Process Explorer...
The AuKill tool abuses an outdated version of the driver used by version 16.32 of...
Apr 20, 2023
Fake Chrome updates spread malware
A campaign running since the end of last year is using hacked sites to push...
Apr 20, 2023
QBot using new attack vector in its...
QBot, also known as QakBot, previously operated as a banking trojan and has since transformed...
Apr 20, 2023
CrossLock Ransomware Emerges: New Golang – Based...
The CrossLock ransomware employs the double extortion technique to increase the likelihood of payment from...
Apr 20, 2023
Windows Zero-Day Vulnerability CVE-2023-28252 Exploited by Nokoyawa...
A zero-day vulnerability in the Microsoft Windows system, which also affects Windows 11, has been...
Apr 18, 2023
Additional IOcs for 3cx breach
Recently an unexpected malicious activity emanating from a legitimate, signed binary, 3CXDesktopApp was observed. As...
Apr 18, 2023
Additional IOcs for 3cx breach
Recently an unexpected malicious activity emanating from a legitimate, signed binary, 3CXDesktopApp was observed. As...
Apr 18, 2023
APT36 Expands Interest Within Indian Education Sector
Symantec described UPS in 2016 report as Buckeye (also known as APT3 Gothic Panda UPS...
Apr 17, 2023
ChinaZ DDoS Bot Malware Distributed To Linux...
The ChinaZ DDoS bot malware was discovered targeting Linux systems while a version for Microsoft...
Apr 16, 2023
Resurgence Of The Mexals Cryptojacking Campaign
The Mexals crypto jacking campaign has been in operation since at least 2021 and continues...