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Cybersecurity Advisories Uncategorized

Vulnerability in XZ Utils Data Compression Library Impacting Multiple Linux Distributions (CVE-2024-3094)

Description of the vulnerability per NIST:

“Malicious code was discovered in the upstream tarballs of xz, starting with version 5.6.0. Through a series of complex obfuscations, the liblzma build process extracts a prebuilt object file from a disguised test file existing in the source code, which is then used to modify specific functions in the liblzma code. This results in a modified liblzma library that can be used by any software linked against this library, intercepting, and modifying the data interaction with this library.”

This vulnerability was intentionally induced by a supply chain attack. Starting in 2021, a suspected Threat Actor started to submit patches to open-source project on GITHUB, eventually focusing on the XZ Utils repository and becoming a co-developer. A fuller timeline of events can be found here. The backdoor/vulnerability was fully introduced in versions 5.6.0 and 5.6.1 of xz utils in February. Most production Linux distributions have not adopted these patches, but please check the following section to confirm that no affected versions are present in your environment.

Affected & Fixed Versions

Recommendations and Mitigations

SecurIT360 Managed SOC Clients:

  • For all active managed SOC EDR clients, we have checked our inventory across products and have already reached out if you have an affected Linux distribution.
  • For all active managed SOC MDR clients, we have also run an external Nessus vulnerability scan looking for affected versions and have again already reached out to any and all affected clients.

Otherwise, if you have any Linux endpoint that we do not monitor that you are concerned may be affected by this vulnerability, you can run a simple command of “xz –version” or “xz ultis –version” on these endpoints to confirm your versioning on the endpoint in question:

If any of your endpoints do presently use 5.6.0 and 5.6.1 of XZ Utils, we would recommend either updating or downgrading packages per the table above. For the case of Fedora 40-41 and Rawhide specifically the recommendation from Red Hat would be to power-down or stop using Rawhide for the time being, and to move to packages 5.4.X for Fedora 40-41. See Red Hat’s blog post on the subject for more information.

Resources & Related Articles

Categories
General Cyber and IT Security Uncategorized

Understanding DNSSEC and DNS Security

In our increasingly interconnected world, where the digital landscape expands every day, safeguarding our online presence has become vital. One fundamental yet often overlooked aspect of online security is Domain Name System (DNS) security. DNS is the backbone of the internet, responsible for translating domain names into IP addresses that computers can understand. To protect this system from threats, DNS security extensions (DNSSEC) plays a pivotal role.

How DNS Works

DNS Attacks

DNS spoofing and DNS cache poisoning are malicious techniques aimed at manipulating the Domain Name System (DNS) to redirect users to fraudulent websites or compromise network security. DNS spoofing involves forging DNS responses to trick a user’s device into believing it has received legitimate information when, in reality, it’s been directed to a malicious site. This can lead to various security breaches, including phishing attacks. On the other hand, DNS cache poisoning involves corrupting a DNS server’s cache with fraudulent data. Once the cache is poisoned, the server can distribute this tainted information to users, redirecting them to attacker-controlled websites. Both DNS spoofing and cache poisoning are serious threats to the integrity of the DNS infrastructure that highlight the importance of DNSSEC.

DNSSEC

DNSSEC is a suite of extensions to DNS that adds an extra layer of security by digitally signing DNS data. This verification process ensures that the data retrieved from DNS servers is authentic and hasn’t been tampered with by malicious actors. Here’s how it works:

  1. Signing Zone Data: DNSSEC involves signing zone data with cryptographic signatures. Each DNS record in a zone is signed using a private key.
  2. Public Key Distribution: The public key for each zone is published in a DNS record called the Delegation Signer (DS) record. This record is stored in the parent zone, creating a chain of trust. The public key is paired with a private key which is typically stored offline. This creates a digital signature which is published to DNS.
  3. Authentication: When a user’s device queries a DNS server for a domain, the server provides not only the requested data but also the corresponding digital signature. The user’s device uses the public key stored in the DS record to verify the signature’s authenticity.
  4. Validation: If the signature is valid, the DNSSEC client trusts the data it received, knowing it hasn’t been altered during transmission.

How DNSSEC Works:

Benefits of DNSSEC:

  1. Data Integrity: DNSSEC ensures that the DNS data remains unchanged, preventing attackers from redirecting users to malicious websites.
  2. Authentication: It guarantees that the data comes from a legitimate source, reducing the risk of DNS spoofing attacks.
  3. Trust Chain: By establishing a trust chain through DS records, DNSSEC enhances the security of the entire DNS hierarchy.

Challenges with DNSSEC:

While DNSSEC offers robust security, its adoption faces some challenges:

  1. Complex Implementation: DNSSEC implementation can be complex and may require significant effort. However, other DNS providers may offer to enable DNSSEC as part of your DNS package.
  2. Compatibility: Not all DNS servers and clients support DNSSEC, which can lead to compatibility issues.
  3. Key Management: Managing cryptographic keys can be challenging and requires careful consideration.
  4. Increased Packet Size: DNSSEC can result in larger DNS responses, which may impact network performance.

Other DNS Security Options:

DNSSEC is a cornerstone of DNS security, but several other extensions complement it:

  1. DNS-based Authentication of Named Entities (DANE): DANE allows domain owners to associate their TLS certificates with DNS records, improving the security of encrypted connections.
  2. Response Policy Zones (RPZ): RPZ enables DNS servers to block or redirect requests to known malicious domains.
  3. DNS-over-HTTPS (DoH) and DNS-over-TLS (DoT): These protocols encrypt DNS traffic, preventing eavesdropping and manipulation.

In conclusion, DNSSEC is an essential component of our digital defense. DNSSEC provides a robust framework for ensuring the integrity and authenticity of DNS data. The benefits of a more secure and trustworthy internet make the adoption of DNS security extensions a worthy investment in our digital future.

 

Categories
Uncategorized

Phishing Attacks and Multifactor Authentication

Stop the Password Reset Insanity

How much time does your IT department spend changing a user’s network and or email account passwords because they clicked on a phishing link that they should not have? How many users do you have who do this repeatedly? Have you trained your users to identify, report, and ignore these phishing attempts?

Why make the only procedure to resolve this resetting the password when it just keeps happening again and again? Stop the insanity and look at a new way of solving this problem.

“The definition of insanity is doing the same thing over and over again and expecting different results.”

How Spearphishing Works

Your company webpage has just been redesigned to provide an enriched marketing experience. It looks great and everyone on your leadership team is excited about the new page. One of the pages, “About Our Team”, lists every member of the executive management team with a short bio. You have just provided the bad guys with a short list of high-value targets within your company.

With this list of users in hand and by utilizing the most standard email address format (everyone uses first initial of the first name + last name), a couple of smart public DNS queries, and a telnet to port 25 of your email server, I can determine your mail server and version, including Microsoft Office 365. Then I can set up a fake webmail account login page and send a well-crafted email asking them to log in to my fake email system so I can steal their password.

Once your user completes this action, I have not just compromised their account, I have compromised an influential person in the company. I now have access to the corporate account of someone who can make decisions and spend money, for example, authorize an invoice to be paid or request a wire transfer. Payday for me, headaches dealing with law enforcement, lawyers, cyber insurance companies, and forensics experts for you.

What Happens Next

Once you discover the intrusion, I’ve been reported to IT, the user’s account password has been changed, the lawyers are doing insurance reviews, and accounting is double checking the books, but I am still out there. While everyone is thinking, crisis averted, I am waiting for the next opportunity.

Now, I sit back and wait a week or two before another attempt. During this time, a business crisis arises, distracting the executives, and I send another email asking you to log in. Nine times out of ten, I get back in. Executives are busy between internal, partner and customer meetings, traveling, reviewing performance numbers, and so on. They are always busy and want things to go smoothly so they can accomplish tasks quickly. Because of this, your executives rarely look twice at the email asking for the password again – just so they can get that PDF report they think they are getting.

So, they are compromised. Again. You change their password. Again. Insanity.

While you are saying to yourself, “This would never happen at my company”, let me share this story with you. I recently worked a case where the President of the company was successfully spearfished three times in two weeks. Each time, the password was reset, and everyone moved on to other things. In another case, a breached IT administrator account was used to spearfish the CFO. As if that is not bad enough, the CFO had already been successfully spearfished two months prior.

How do I end this cycle?

The easy answer is to require multi-factor authentication (MFA). The harder question is, “How do I implement MFA without being chased with pitchforks and firebrands?” Or worse yet, isolated in an office in the basement with your career stalled out.

So, how do you implement MFA while minimizing the impact on your users?

Scenario 1:

IT develops a MFA implementation plan. They then meet with the executives to outline the program’s pros and cons, with the strategy of scaring them into agreeing to implement MFA. They use statistics from Gartner, include quotes from Verizon’s Annual Data Breach Investigation Report, and try to sell the implementation plan. Remember, these are the same executives who are busy moving from one fire drill to another while being spearfished daily. This strategy almost never goes well.

Scenario 2:

IT develops a MFA implementation plan. Instead of only using statistics from Gartner and quotes from Verizon’s Annual Data Breach Investigation report, they use actual internal data to affect change from within. Prior to presenting this data, they have already completed a MFA pilot with their Email administrators and then rolled it out to the entire IT department. Here’s the payoff: report the measured results of the rollout to the IT Steering Committee, CFO, or COO; the point is, get an executive to start thinking about MFA, hearing the results, and digesting the successes. Then, get that individual to try it.

Peer pressure can also be beneficial in this scenario. “One-Upmanship” within a highly political boardroom can be a good thing. Having someone inside the decision-making group proudly boasting how fourteen unauthorized attempts to log in to their account were thwarted by MFA can provide the incentive you need. No one wants to be the weak link or in last place.

The Benefits of MFA

Now that you have implemented MFA, you are able to stop the insanity of repeatedly resetting passwords, re-imaging computers, spending hours on telephone calls with lawyers, insurance companies, and forensics companies. You can expect fewer security headaches, more time to complete your projects, and your executive team to appreciate how secure your network has become with multi-factor authentication.

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Categories
Uncategorized

WannaCry – Worldwide Ransomware Attack – Updated

A widespread ransomware attack has spread across the globe infecting tens of thousands computers in as many countries, including the United States, United Kingdom, Spain, Russia, Taiwan, France, and Japan.  The software can run in many languages.  There have been several versions and updates, but the ways to protect remain the same.  Recently, a decryption tool has been discovered – see here.

Technical Details

Initial reports indicate the hacker or hacking group behind the WannaCry campaign is gaining access to enterprise servers either through a Remote Desktop Protocol (RDP) compromise or the exploitation of a critical Windows SMB vulnerability.  Microsoft released a security update for the MS17-010 vulnerability on March 14, 2017.  According to open sources, one possible infection vector is via phishing emails.

The WannaCry ransomware received and analyzed by US-CERT is a loader that contains an AES-encrypted DLL.  During runtime, the loader writes a file to disk named “t.wry.”  The malware then uses an embedded 128-bit key to decrypt this file.  This DLL, is then loaded into the parent process, is the actual Wanna Cry Ransomware responsible for encrypting the user’s files.  Using this cryptographic loading method, the WannaCry DLL is never directly exposed on disk and not vulnerable to antivirus software scans.  Subsequent versions are manifested differently.

What to do to protect against Wana Decrypt0r aka WannaCry

1.    Patch all Windows Operating Systems

  1. For supported Operating Systems see MS17-010
  2. Emergency Patch for Windows XP and Windows 2003 is here

2.    Run a port scan and or Vulnerability Assessment against your firewalls. 

Ensure that Remote Desktop Protocol (RDP) and SMB protocols are not open to the internet.  These are typically on ports 3389, 445, and 139 respectively, but can be mapped to different ports on your firewall.  These configurations are security best practice.

Verify Other Protections Are working as expected.

*************************************IMPORTANT******************************************
Do NOT assume you are safe just because you have purchased and installed a product.
**********************************************************************************************

3.    Backups

Review your backups to ensure that they are working as expected.  Test restores of critical data.

4.    SPAM Filter

Enable strong spam filters to prevent phishing e-mails from reaching the end users.  Most enterprise filters should detect WannaCry.

5.    Antivirus & Malware Protections

  1. Ensure that real-time scanning enabled to detect file downloads, email attachments, and web links
  2. Ensure that scan engines are up to date and that definitions are downloaded and regularly deployed – at least daily. We recommend more frequently
  3. Configure anti-virus and anti-malware solutions to conduct routine scans
  4. Inventory protected machines to ensure that all have products installed and that they are functional

WannaCry Remediation

  • Isolate compromised computer systems.
    1. Unplug from network to prevent spreading
    2. Power down other computers or unplug network access switches during eradication
    3. Wipe and reload infected machines
    4. Paying the ransom does not guarantee you recovery
  • Ensure that proper logging is enabled and preserved on key systems.
  • Contact law enforcement. Contact a local FBI field office upon discovery to report an intrusion and request assistance.  Maintain and provide relevant logs.
  • Implement your security incident response and business continuity plan.
  • Ideally, organizations should not store critical data on workstations. Critical data should reside on centralized storage systems.  Storage systems should have complete, verified, and tested backups.  Ofen the most efficient response is to restore data from a known clean backup.

Signatures

File name:  @WanaDecryptor@.exe

Confirmed indicators – SHA-256 Hashes:

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

Yara Signatures

rule Wanna_Cry_Ransomware_Generic {

meta:

description = “Detects WannaCry Ransomware on disk and in virtual page”

author = “US-CERT Code Analysis Team”

reference = “not set”

date = “2017/05/12”

hash0 = “4DA1F312A214C07143ABEEAFB695D904”

strings:

$s0 = {410044004D0049004E0024}

$s1 = “WannaDecryptor”

$s2 = “WANNACRY”

$s3 = “Microsoft Enhanced RSA and AES Cryptographic”

$s4 = “PKS”

$s5 = “StartTask”

$s6 = “wcry@123”

$s7 = {2F6600002F72}

$s8 = “unzip 0.15 Copyrigh”

condition:

$s0 and $s1 and $s2 and $s3 or $s4 or $s5 or $s6 or $s7 or $s8

}

/*The following Yara ruleset is under the GNU-GPLv2 license (http://www.gnu.org/licenses/gpl-2.0.html) and open to any user or organization, as long as you use it under this license.

rule MS17_010_WanaCry_worm {

meta:

description = “Worm exploiting MS17-010 and dropping WannaCry Ransomware”

author = “Felipe Molina (@felmoltor)”

reference = “https://www.exploit-db.com/exploits/41987/”

date = “2017/05/12”

strings:

$ms17010_str1=”PC NETWORK PROGRAM 1.0″

$ms17010_str2=”LANMAN1.0″

$ms17010_str3=”Windows for Workgroups 3.1a”

$ms17010_str4=”__TREEID__PLACEHOLDER__”

$ms17010_str5=”__USERID__PLACEHOLDER__”

$wannacry_payload_substr1 = “h6agLCqPqVyXi2VSQ8O6Yb9ijBX54j”

$wannacry_payload_substr2 = “h54WfF9cGigWFEx92bzmOd0UOaZlM”

$wannacry_payload_substr3 = “tpGFEoLOU6+5I78Toh/nHs/RAP”

condition:

all of them

}