Malicious pdf file analysis

Fyi running pdf in sandbox environment can give much insight related to indicators of compromise. For testing purposes, i created a pdf file that contains a doc file that drops the eicar test file. Signature and security product testing often requires large numbers of sorted malicious and clean files to eliminate false positives and negatives. Automated malware analysis joe sandbox cloud basic. For these reasons, its good to know how to analyze pdf files, but analysts first need a basic understanding of a pdf before they deem it malicious. A technical analysis of a paypal phishing scam evaluating. Malicious documents pdf analysis in 5 steps count upon. Analysing malicious email files lemons infosec ramblings. This starts a series of post leading up to my pdf talk at the next belgian issa and owasp chapter event. Malicious pdf files are frequently used as part of targeted and massscale computer attacks. Joe sandbox detects and analyzes potential malicious files and urls on windows, android, mac os, linux, and ios for suspicious activities. Here are 6 free tools you can install on your system and use for this purpose. Hybrid analysis develops and licenses analysis tools to fight malware.

Analyzing pdf malware part 1 trustwave spiderlabs trustwave. If you disagree with the scan result, you can send the file or link. Microsoft security researchers analyze suspicious files to determine if they are threats, unwanted applications, or normal files. Almost every post on this site has pcap files or malware samples or both. In this blogpost i examine some malicious office and pdf documents and i will give you some information about their analysis process and. It is widely used for personal as well as official communication channels. With pyv8 and pylibemu installed you can also use it to analyse javascript and shellcode. Even if you were somehow able to know exactly what that pdf file s malicious content is capable of, theres no way to ensure it hasnt been tampered with to masquerade.

Feature analysis of encrypted malicious traffic article pdf available in expert systems with applications 125 february 2019 with 907 reads how we measure reads. In other words, a malicious pdf or ms office document received via email or opened trough a browser plugin. Its good to know how to analyze pdf files, but analysts first need a. Locate embedded code, such as shellcode, vba macros, javascript or other suspicious objects. Peepdf, a new tool from jose miguel esparza, is an excellent addition to the pdf analysis toolkit for examining and decoding suspicious pdfs. We can safely open a pdf file in a plain text editor to inspect its contents. Malicious documents pdf analysis in 5 steps mass mailing or targeted campaigns that use common files to host or exploit code have been and are a very popular vector of attack.

A false detection is a situation when a threat is detected in a safe file or link. As you have seen in this article and last article, there is a procedure which analysts must follow to identify properly, locate, extract and deobfuscate and further analyze embedded scripts in such malicious documents. More info on our pdf examiner for detection and analysis of malicious pdfs. This tools lends itself well to manual pdf analysis tasks. This process can confirm whether the file is malicious, provide some of the information about its functionality.

Next video shows how i use my pdf parser to analyze a malicious pdf file, and extract the shell code. Over at the sans isc diary i wrote a diary entry on the analysis of a pdf file that contains a malicious doc file. This website gives you access to the community edition of joe sandbox cloud. Peepdf is a tool for forensic analysis of pdf documents. For more information, read the submission guidelines. Basic static analysis is a straightforward process and can be quick but it is largely ineffective where the malware file is too complex to understand. In the last few days i have done some analysis on malicious documents, especially pdf.

Pdf examiner by malware tracker is able to scan the uploaded pdf for several known exploits, allows the user to explore the structure of the file, as well as examine, decode and dump pdf object contents. Support for basic pdf javascript deobfuscation, encrypted pdfs rsa, aesv2, revision 5 aesv3. Most of the obfuscation technique are mainly using javascript obfuscation like eval, omcharcode, arguments. Attackers continue to use malicious pdf files as part of targeted attacks and massscale clientside exploitation. Uncheck allow nonpdf file attachments with external applications to prevent launch action vulnerability.

In case the pdf file contains javascript, the malicious code is used to trigger a vulnerability and to execute shellcode. Pdf examiner by malware tracker is able to scan the uploaded pdf for sveral known expoits, allows the user to explore the structure of the file, as well as examine, decode and dump pdf object contents. I found something strange in the pdf file than the other malicious pdf files. Tools and techniques for fighting malicious code published by. Automate malware pdf analysis and step through the objects of a malicious pdf. We will analyze it using a blend of both static and dynamic methodologies.

Their background is also to help explore malicious pdfs but i also find it useful to analyze the structure and contents of benign pdf files. As for the targeted attacks, the modus operandi remains similar to random target. Reports of limited new sandbox bypass on windows in cve20140546. In the next part of series, we will look into more complex examples and will see the methods to parse the contents from those malicious documents. Next video shows how i use my pdf parser to analyze a malicious pdf file, and extract the shell.

Dissect pdf streams to discover new and known exploits. Submit malware for free analysis with falcon sandbox and hybrid analysis technology. Analyzing a pdf file involves examining, decoding, and extracting the contents of suspicious pdf objects that may be used to exploit a vulnerability in adobe reader and execute a malicious payload. We can say all of the inthewild or targetted attack using malicious pdf file are covered with obfuscation techniques to hardened the analysis or detection process. Support for basic pdf javascript obfuscation, encrypted pdfs rsa, aesv2, revision 5 aesv3. Free automated malware analysis service powered by falcon sandbox. Malicious pdf analysis evasion techniques trendlabs. Using feedback provided by the smart protection network, we. Malware tracker limited home of cryptam for extracting encrypted embedded malware executables from phishing attacks, pdf malware detection and analysis with pdfexaminer. Word documents, pdfs, photos, and other types of files that are infected with viruses endanger the security of your system every day and cause more computers to be infected.

Creating and analyzing a malicious pdf file with pdf. Since the summer of 20, this site has published over 1,600 blog entries about malware or malicious network traffic. In many exploit kits, malicious pdf files are some of the most common threats used to try to infect users with various malicious files. Kaspersky virusdesk can detect which type of file encrypting malware was used, but it cannot decrypt files. Malicious pdfs revealing the techniques behind the attacks. There is an increasing number of tools that are designed to assist with this process. Always install the latest patchupdate, even for older adobe product versions.

We just have to submit the malicious pdf file and the online analyzer. Passing stream data through filters flatedecode,asciihexdecode, ascii85decode, lzwdecode and runlengthdecode. This concluded the static analysis of the code, i also did a live dynamic analysis of the malware that i might share at a later time, but for now, let the static analysis do. Its popularity makes it target of malware attackers. Free automated malware analysis service powered by. Submit files you think are malware or files that you believe have been incorrectly classified as malware. Pdf feature analysis of encrypted malicious traffic. To restore your files, use our free decryption tools. Microsoft word documents, a zip or rar files, adobe pdf documents, or even image and video files. In this way, it differs from jsunpack and wepawet, which focus on automating the analysis as much as possible. Although the pdf document still remained on the server the last time i checked. Malicious documents pdf analysis in 5 steps count upon security. Using my pdf parser to analyze a malicious pdf file and to extract the shell code.

This post covers the static analysis of pdf document to identify suspicious objects. Being the most common email attachment, pdf is commonly targeted to. Examine the document for anomalies, such as risky tags, scripts, or other anomalous aspects. Removing malware from a malicious pdf file duplicate ask question asked 4 years. Pdf portable document format is a file format for electronic documents and as with other popular document formats, it can be used by attackers to deliver malware. So, in this article, we have seen some basics and initial concepts around analyzing malicious files. Remove pdf malware by reprinting to new pdf or text extract. But after some googling i found that the same technique was exposed in 2010 so it was not a new technique. The pdf file contains javascript that extracts and opens the doc file with user approval. A pdf file is essentially just a header, some objects inbetween, and then a trailer. Removing malware from a malicious pdf file information. In this way, it differs from jsunpack and wepawet, which focus on automating the analysis.

How can i tell if a pdf file i was sent contains malware. We have created the pdf file with an exe file embedded with it. Analyzing malicious documents cheat sheet sans forensics. Malicious pdf analysis workshop part 2 exercise 1 duration. One of the ways was by sending users an email with a link to a pdf file or by attaching the malicious pdf file directly to trap victim s to open the files.

It performs deep malware analysis and generates comprehensive and detailed analysis reports. Targeted attacks using older patched exploits are common. Though not always vulnerable and infected but some pdfs can have virus or another hidden malware. Yesterday, i downloaded a malicious pdf file for my regular analysis. Analysing malicious pdf documents using dockerized tools. A set of screencasts of my malicious pdf analysis workshop. The file was using a different kind of technique and i was not aware about it.

Analyzing malicious documents cheat sheet lenny zeltser. Analyzing malicious documents this cheat sheet outlines tips and tools for analyzing malicious documents, such as microsoft office, rtf and adobe acrobat pdf files. The exploit takes advantage of software vulnerabilities and then downloads the intended malicious software, called a payload, to the computer. How do attackers turn a pdf into a malicious attack vector. Automate your security operations and incident response with genetic malware analysis. Naturally, security vendors invest in efforts to detect these files properly and their creators invest in efforts to evade those vendors. Malware and its types malware, short for malicious software, consists of programming code, scripts, active content, and other software designed to disrupt or deny operation, gather information that leads to loss of privacy or exploitation, gain unauthorized access to system resources, and other abusive behavior. This tool lends itself well to manual pdf analysis tasks. Malware analysis of the attachments is a little beyond the scope of this blog post, however i wanted to ensure that incident responders are better equipt to extract information from malicious emails using a safer method than microsoft outlook or another email client to view malicious files. Then i thought, why not turn a pdf analysis into an. Submit a file for malware analysis microsoft security.