On Sept. 16, 2021, the US Cybersecurity and Infrastructure Security Agency (CISA) released an alert warning that advanced persistent threat (APT) actors were actively exploiting newly identified vulnerabilities in a self-service password management and single sign-on solution known as ManageEngine ADSelfService Plus. The alert explained that malicious actors were observed deploying a specific webshell and other techniques to maintain persistence in victim environments; however, in the days that followed, we observed a second unrelated campaign carry out successful attacks against the same vulnerability.
As early as Sept. 17 the actor leveraged leased infrastructure in the United States to scan hundreds of vulnerable organizations across the internet. Subsequently, exploitation attempts began on Sept. 22 and likely continued into early October. During that window, the actor successfully compromised at least nine global entities across the technology, defense, healthcare, energy and education industries.
Source: Palo Alto/Unit 42