{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/adobe-acrobat-reader/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Adobe Acrobat Reader","Adobe Acrobat","Foxit PDF Reader","Foxit PDF Editor"],"_cs_severities":["medium"],"_cs_tags":["exploitation","pdf","initial-access"],"_cs_type":"advisory","_cs_vendors":["Adobe","Foxit"],"content_html":"\u003cp\u003eAttackers frequently target PDF reader applications due to their widespread use and complex codebase, providing multiple avenues for exploitation. These exploits can range from memory corruption vulnerabilities to logic flaws that allow arbitrary code execution. Social engineering is also a common tactic, where users are tricked into opening malicious PDF files that trigger the execution of embedded scripts or commands. The spawned processes often include system utilities used for reconnaissance or persistence. This technique is used for initial access, defense evasion, and discovery within the targeted environment. The detection rule provided by Elastic identifies suspicious child processes of PDF reader applications.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eA user receives a spearphishing email with a malicious PDF attachment (T1566.001).\u003c/li\u003e\n\u003cli\u003eThe user opens the PDF file using a vulnerable PDF reader application (e.g., Acrobat Reader, Foxit Reader).\u003c/li\u003e\n\u003cli\u003eThe PDF file exploits a vulnerability in the PDF reader, triggering the execution of embedded JavaScript or shell commands (T1203, T1204.002).\u003c/li\u003e\n\u003cli\u003eThe exploited PDF reader process (AcroRd32.exe, Acrobat.exe, FoxitPhantomPDF.exe, FoxitReader.exe) spawns a suspicious child process such as \u003ccode\u003ecmd.exe\u003c/code\u003e or \u003ccode\u003epowershell.exe\u003c/code\u003e (T1059.001).\u003c/li\u003e\n\u003cli\u003eThe spawned process executes discovery commands (e.g., \u003ccode\u003ewhoami.exe\u003c/code\u003e, \u003ccode\u003esysteminfo.exe\u003c/code\u003e, \u003ccode\u003enet.exe\u003c/code\u003e, \u003ccode\u003eipconfig.exe\u003c/code\u003e) to gather information about the system and network (T1082, T1016, T1033, T1057).\u003c/li\u003e\n\u003cli\u003eThe attacker may use system binary proxy execution (T1218) techniques by invoking utilities such as \u003ccode\u003emshta.exe\u003c/code\u003e, \u003ccode\u003eregsvr32.exe\u003c/code\u003e, or \u003ccode\u003einstallutil.exe\u003c/code\u003e to execute malicious code.\u003c/li\u003e\n\u003cli\u003eThe attacker establishes persistence on the system, potentially using scheduled tasks (\u003ccode\u003eschtasks.exe\u003c/code\u003e) or registry modifications (\u003ccode\u003ereg.exe\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eThe attacker moves laterally within the network, escalating privileges, and exfiltrating sensitive data, or deploying ransomware.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eCompromised systems can lead to data theft, system disruption, and further propagation of the attack within the network. Successful exploitation of PDF reader vulnerabilities can provide attackers with initial access to the target environment, potentially impacting hundreds or thousands of machines across an organization. The impact can range from minor data breaches to full-scale ransomware deployment, depending on the attacker's objectives.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026quot;Suspicious PDF Reader Child Process\u0026quot; to your SIEM to detect suspicious child processes spawned by PDF readers.\u003c/li\u003e\n\u003cli\u003eEnable process creation logging, specifically monitoring for \u003ccode\u003eAcroRd32.exe\u003c/code\u003e, \u003ccode\u003eAcrobat.exe\u003c/code\u003e, \u003ccode\u003eFoxitPhantomPDF.exe\u003c/code\u003e, and \u003ccode\u003eFoxitReader.exe\u003c/code\u003e spawning command-line interpreters or other suspicious utilities.\u003c/li\u003e\n\u003cli\u003eEnsure PDF reader applications are patched to the latest versions to mitigate known vulnerabilities.\u003c/li\u003e\n\u003cli\u003eImplement email filtering to block suspicious attachments and educate users about the risks of opening unsolicited PDF files.\u003c/li\u003e\n\u003cli\u003eMonitor network connections originating from PDF reader applications for unusual outbound traffic.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-suspicious-pdf-child-process/","summary":"Adversaries may exploit vulnerabilities in PDF reader applications or use social engineering to execute malicious commands, often spawning system utilities for discovery or defense evasion purposes.","title":"Suspicious PDF Reader Child Process Execution","url":"https://feed.craftedsignal.io/briefs/2024-01-suspicious-pdf-child-process/"},{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Adobe Acrobat Reader","Adobe"],"_cs_severities":["medium"],"_cs_tags":["persistence","process-injection","adobe"],"_cs_type":"advisory","_cs_vendors":["Adobe"],"content_html":"\u003cp\u003eThis brief discusses a potential persistence technique involving the hijacking of Adobe-related processes or components. While specific details of observed campaigns are unavailable, this technique exploits the trust associated with legitimate Adobe software to maintain a foothold on a compromised system. By replacing or modifying Adobe binaries or libraries with malicious versions, attackers can ensure their code is executed whenever the legitimate Adobe software is launched. This approach allows malware to evade detection by blending in with trusted processes and potentially bypassing security measures that are configured to allow Adobe software to run unhindered. Given the widespread use of Adobe products, this presents a significant risk to a broad range of systems.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eInitial access is gained through an unknown method (e.g., exploiting a vulnerability in a different application, or social engineering).\u003c/li\u003e\n\u003cli\u003eThe attacker identifies a suitable Adobe process or component to hijack (e.g., AcroRd32.exe, AdobeUpdate.exe).\u003c/li\u003e\n\u003cli\u003eThe attacker replaces the legitimate Adobe binary with a malicious executable or modifies an existing Adobe DLL to inject malicious code.\u003c/li\u003e\n\u003cli\u003eThe attacker establishes persistence by ensuring the modified Adobe component is launched automatically upon system startup or user login (e.g., via registry keys, scheduled tasks, or startup folders).\u003c/li\u003e\n\u003cli\u003eWhen the user or system launches the legitimate Adobe application, the malicious code is executed, providing the attacker with control.\u003c/li\u003e\n\u003cli\u003eThe attacker uses the compromised process to perform malicious activities such as downloading additional payloads, exfiltrating data, or establishing command and control.\u003c/li\u003e\n\u003cli\u003eThe attacker attempts to maintain stealth by masquerading as a legitimate Adobe process and avoiding detection by security tools.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this technique could allow attackers to maintain long-term, persistent access to a compromised system. This could result in data theft, system compromise, and potential disruption of business operations. Due to the trusted nature of Adobe applications, this technique can be difficult to detect and remediate, potentially affecting a large number of users and organizations across various sectors.\u003c/p\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-adobe-hijack/","summary":"This brief outlines a potential persistence mechanism involving hijacking Adobe-related processes or components, which could allow attackers to maintain unauthorized access to a system.","title":"Potential Adobe Hijack Persistence Mechanism","url":"https://feed.craftedsignal.io/briefs/2024-01-adobe-hijack/"},{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Adobe Acrobat Reader"],"_cs_severities":["low"],"_cs_tags":["persistence","adobe","file-replacement"],"_cs_type":"advisory","_cs_vendors":["Adobe"],"content_html":"\u003cp\u003eThis threat focuses on the potential hijacking of Adobe Acrobat Reader by replacing its \u003ccode\u003eRdrCEF.exe\u003c/code\u003e executable with a malicious file. This technique allows attackers to establish persistence on a compromised system. When a user launches Adobe Acrobat Reader, the replaced \u003ccode\u003eRdrCEF.exe\u003c/code\u003e is executed, granting the attacker continued access. This is a potential persistence mechanism which could allow for the deployment of malware, exfiltration of data, or further compromise of the system. The original detection rule was created in February 2020 and has been updated multiple times with the last update on April 7, 2026.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker gains initial access to the system, potentially through exploiting a vulnerability or social engineering.\u003c/li\u003e\n\u003cli\u003eThe attacker identifies the location of the \u003ccode\u003eRdrCEF.exe\u003c/code\u003e file within the Adobe Acrobat Reader installation directory (e.g., \u003ccode\u003eC:\\Program Files (x86)\\Adobe\\Acrobat Reader DC\\Reader\\AcroCEF\\RdrCEF.exe\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eThe attacker replaces the legitimate \u003ccode\u003eRdrCEF.exe\u003c/code\u003e file with a malicious executable. This could involve renaming the original file and placing the malicious file in its place, or overwriting the original file directly.\u003c/li\u003e\n\u003cli\u003eThe attacker ensures the malicious executable has the same name as the original \u003ccode\u003eRdrCEF.exe\u003c/code\u003e file.\u003c/li\u003e\n\u003cli\u003eA user launches Adobe Acrobat Reader.\u003c/li\u003e\n\u003cli\u003eThe operating system executes the \u003ccode\u003eRdrCEF.exe\u003c/code\u003e file as part of Adobe Acrobat Reader's startup process.\u003c/li\u003e\n\u003cli\u003eBecause the file has been replaced with a malicious executable, the attacker's code is executed.\u003c/li\u003e\n\u003cli\u003eThe attacker maintains persistent access to the system and can perform further actions such as deploying malware or exfiltrating data.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this technique allows attackers to maintain persistence on compromised systems. This can lead to the deployment of ransomware, exfiltration of sensitive data, or further exploitation of the system. The severity is low, but impact can be high, if the adversary uses this technique to gain further access to the compromised system.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026quot;Adobe Acrobat Reader Hijack for Persistence\u0026quot; to your SIEM to detect the replacement of the RdrCEF.exe file.\u003c/li\u003e\n\u003cli\u003eMonitor file creation events in the Adobe Acrobat Reader installation directories for suspicious executables using Sysmon or another EDR solution.\u003c/li\u003e\n\u003cli\u003eRegularly audit file integrity within the Adobe Acrobat Reader installation directory to identify unauthorized modifications.\u003c/li\u003e\n\u003cli\u003eInvestigate any alerts generated by the Sigma rules or other detection mechanisms to determine if a system has been compromised.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-02T18:22:00Z","date_published":"2024-01-02T18:22:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-adobe-hijack-persistence/","summary":"Attackers can maintain persistence by replacing the legitimate RdrCEF.exe file, used by Adobe Acrobat Reader, with a malicious executable that will be launched upon execution of Adobe Acrobat Reader.","title":"Adobe Acrobat Reader Hijack for Persistence","url":"https://feed.craftedsignal.io/briefs/2024-01-adobe-hijack-persistence/"}],"language":"en","title":"CraftedSignal Threat Feed - Adobe Acrobat Reader","version":"https://jsonfeed.org/version/1.1"}