Category: security

KnowBe4 said the fake employee likely had his workstation connected “to an address that is basically an ‘IT mule laptop farm.'” They’d then use a VPN to work the night shift from where they actually reside — in this case, North Korea “or over the border in China.” That work would take place overnight, making it appear that they’re logged on during normal U.S. business hours. “The scam is that they are actually doing the work, getting paid well, and give a large amount to North Korea to fund their illegal programs,” Sjouwerman wrote. “I don’t have to tell you about the severe risk of this.” Despite the intrusion, Sjouwerman said “no illegal access was gained, and no data was lost, compromised, or exfiltrated on any KnowBe4 systems.” He chalked up the incident to a threat actor that “demonstrated a high level of sophistication in creating a believable cover identity” and identified “weaknesses in the hiring and background check processes.”

After gaining access to the Solaris enclave, the red team discovered they couldn’t pivot into the Windows part of the network because missing credentials blocked their path, despite enjoying months of access to sensitive web apps and databases. Undeterred, CISA managed to make its way into the Windows network after carrying out phishing attacks on unidentified members of the target agency, one of which was successful. It said real adversaries may have instead used prolonged password-praying attacks rather than phishing at this stage, given that several service accounts were identified as having weak passwords. After gaining that access, the red team injected a persistent RAT and later discovered unsecured admin credentials, which essentially meant it was game over for the agency being assessed. “None of the accessed servers had any noticeable additional protections or network access restrictions despite their sensitivity and critical functions in the network,” CISA said.

CISA described this as a “full domain compromise” that gave the attackers access to tier zero assets — the most highly privileged systems. “The team found a password file left from a previous employee on an open, administrative IT share, which contained plaintext usernames and passwords for several privileged service accounts,” the report reads. “With the harvested Lightweight Directory Access Protocol (LDAP) information, the team identified one of the accounts had system center operations manager (SCOM) administrator privileges and domain administrator privileges for the parent domain. “They identified another account that also had administrative permissions for most servers in the domain. The passwords for both accounts had not been updated in over eight years and were not enrolled in the organization’s identity management (IDM).” From here, the red team realized the victim organization had trust relationships with multiple external FCEB organizations, which CISA’s team then pivoted into using the access they already had.

The team “kerberoasted” one partner organization. Kerberoasting is an attack on the Kerberos authentication protocol typically used in Windows networks to authenticate users and devices. However, it wasn’t able to move laterally with the account due to low privileges, so it instead used those credentials to exploit a second trusted partner organization. Kerberoasting yielded a more privileged account at the second external org, the password for which was crackable. CISA said that due to network ownership, legal agreements, and/or vendor opacity, these kinds of cross-organizational attacks are rarely tested during assessments. However, SILENTSHIELD assessments are able to be carried out following new-ish powers afforded to CISA by the FY21 National Defense Authorization Act (NDAA), the same powers that also allow CISA’s Federal Attack Surface Testing (FAST) pentesting program to operate. It’s crucial that these avenues are able to be explored in such exercises because they’re routes into systems adversaries will have no reservations about exploring in a real-world scenario. For the first five months of the assessment, the target FCEB agency failed to detect or remediate any of the SILENTSHIELD activity, raising concerns over its ability to spot genuine malicious activity. CISA said the findings demonstrated the need for agencies to apply defense-in-depth principles. The cybersecurity agency recommended network segmentation and a Secure-by-Design commitment.

On Wednesday, CDK Global told dealerships that it’s “investigating a cyber incident” and “proactively shut all systems down” while addressing the issue. However, as reported by Automotive News, CDK Global restored its systems shortly after, only to shut them down hours later due to “an additional cyber incident.”

CVE-2024-4577 affects PHP only when it runs in a mode known as CGI, in which a web server parses HTTP requests and passes them to a PHP script for processing. Even when PHP isn’t set to CGI mode, however, the vulnerability may still be exploitable when PHP executables such as php.exe and php-cgi.exe are in directories that are accessible by the web server. This configuration is extremely rare, with the exception of the XAMPP platform, which uses it by default. An additional requirement appears to be that the Windows locale — used to personalize the OS to the local language of the user — must be set to either Chinese or Japanese. The critical vulnerability was published on June 6, along with a security patch. Within 24 hours, threat actors were exploiting it to install TellYouThePass, researchers from security firm Imperva reported Monday. The exploits executed code that used the mshta.exe Windows binary to run an HTML application file hosted on an attacker-controlled server. Use of the binary indicated an approach known as living off the land, in which attackers use native OS functionalities and tools in an attempt to blend in with normal, non-malicious activity.

In a post published Friday, Censys researchers said that the exploitation by the TellYouThePass gang started on June 7 and mirrored past incidents that opportunistically mass scan the Internet for vulnerable systems following a high-profile vulnerability and indiscriminately targeting any accessible server. The vast majority of the infected servers have IP addresses geolocated to China, Taiwan, Hong Kong, or Japan, likely stemming from the fact that Chinese and Japanese locales are the only ones confirmed to be vulnerable, Censys researchers said in an email. Since then, the number of infected sites — detected by observing the public-facing HTTP response serving an open directory listing showing the server’s filesystem, along with the distinctive file-naming convention of the ransom note — has fluctuated from a low of 670 on June 8 to a high of 1,800 on Monday. Censys researchers said in an email that they’re not entirely sure what’s causing the changing numbers.

“The vulnerability, tracked as CVE-2024-1086 and carrying a severity rating of 7.8 out of a possible 10, allows people who have already gained a foothold inside an affected system to escalate their system privileges.”

It’s the result of a use-after-free error, a class of vulnerability that occurs in software written in the C and C++ languages when a process continues to access a memory location after it has been freed or deallocated. Use-after-free vulnerabilities can result in remote code or privilege escalation. The vulnerability, which affects Linux kernel versions 5.14 through 6.6, resides in the NF_tables, a kernel component enabling the Netfilter, which in turn facilitates a variety of network operations… It was patched in January, but as the CISA advisory indicates, some production systems have yet to install it. At the time this Ars post went live, there were no known details about the active exploitation.

A deep-dive write-up of the vulnerability reveals that these exploits provide “a very powerful double-free primitive when the correct code paths are hit.” Double-free vulnerabilities are a subclass of use-after-free errors…

Both of these are abundantly clear even to our peers in disciplines outside software engineering. This to me makes it worth using them from a clarity perspective alone. But then we have the big benefit to abstractions, as well. When we call both by the same word, there’s often an urge to combine them into a single module just by dint of the terminology. This isn’t necessarily wrong — there is certainly some merit to put them together, since permissions typically require a login. But it’s not necessary, either, and our designs will be stronger if we don’t make that assumption and instead make a reasoned choice.

The mseal system call was led by Jeff Xu of Google’s Chrome team. The goal with memory sealing is to also protect the memory mapping itself against modification. The new mseal Linux documentation explains:

“Modern CPUs support memory permissions such as RW and NX bits. The memory permission feature improves security stance on memory corruption bugs, i.e. the attacker can’t just write to arbitrary memory and point the code to it, the memory has to be marked with X bit, or else an exception will happen. Memory sealing additionally protects the mapping itself against modifications. This is useful to mitigate memory corruption issues where a corrupted pointer is passed to a memory management system… Memory sealing can automatically be applied by the runtime loader to seal .text and .rodata pages and applications can additionally seal security-critical data at runtime. A similar feature already exists in the XNU kernel with the VM_FLAGS_PERMANENT flag and on OpenBSD with the mimmutable syscall.”
The mseal system call is designed to be used by the likes of the GNU C Library “glibc” while loading ELF executables to seal non-writable memory segments or by the Google Chrome web browser and other browsers for protecting security sensitive data structures.

Cybersecurity and cryptocurrency researchers told WIRED last month that Change Healthcare appeared to have paid that ransom on March 1, pointing to a transaction of 350 bitcoins or roughly $22 million sent into a crypto wallet associated with the AlphV hackers. That transaction was first highlighted in a message on a Russian cybercriminal forum known as RAMP, where one of AlphV’s allegedly jilted partners complained that they hadn’t received their cut of Change Healthcare’s payment. However, for weeks following that transaction, which was publicly visible on Bitcoin’s blockchain and which both security firm Recorded Future and blockchain analysis firm TRM Labs told WIRED had been received by AlphV, Change Healthcare repeatedly declined to confirm that it had paid the ransom.

Change Healthcare’s confirmation of that extortion payment puts new weight behind the cybersecurity industry’s fears that the attack — and the profit AlphV extracted from it — will lead ransomware gangs to further target health care companies. “It 100 percent encourages other actors to target health care organizations,” Jon DiMaggio, a researcher with cybersecurity firm Analyst1 who focuses on ransomware, told WIRED at the time the transaction was first spotted in March. “And it’s one of the industries we don’t want ransomware actors to target — especially when it affects hospitals.” Compounding the situation, a conflict between hackers in the ransomware ecosystem has led to a second ransomware group claiming to possess Change Healthcare’s stolen data and threatening to sell it to the highest bidder on the dark web. Earlier this month that second group, known as RansomHub, sent WIRED alleged samples of the stolen data that appeared to come from Change Healthcare’s network, including patient records and a contract with another health care company.

“On April 14, 2024, Frontier Communications Parent, Inc. [..] detected that a third party had gained unauthorized access to portions of its information technology environment,” the company revealed in a filing with the U.S. Securities and Exchange Commission on Thursday. “Based on the Company’s investigation, it has determined that the third party was likely a cybercrime group, which gained access to, among other information, personally identifiable information.” Frontier now believes that it has contained the breach, has since restored its core IT systems affected during the incident, and is working on restoring normal business operations.