Hi again, this is Shusei Tomonaga from the Analysis Center. In this article, I’d like to share some of our findings about ChChes (which we introduced in a previous article) that it leverages PowerSploit [1] – an open source tool – for infection. Flow of ChChes Infection The samples that JPCERT/CC confirmed this time infect machines by leveraging shortcut files. The flow of events from a victim opening the shortcut...
List of “朝長 秀誠 (Shusei Tomonaga)”
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Hi again, this is Shusei Tomonaga from the Analysis Center. PlugX is a type of malware used for targeted attacks. We have introduced its new features in the blog article “Analysis of a Recent PlugX Variant - ‘P2P PlugX‘”. This article will discuss the following two structural changes observed in PlugX since April 2016: the way API is called the format of main module changed from PE to raw binary...
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When analysing Windows executable file type (PE file) malware, a tool to parse and display the PE file’s structure (hereafter “PE analysis tool”) is often used. This tool enables referring to a list of APIs that the malware imports (Import API) and functions that it exports. By analysing the data, it is possible to presume the malware’s function as in communicating with external servers or creating registry entries, etc. In...
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Hi again, this is Shusei Tomonaga from the Analysis Center. Today I will introduce a tool “impfuzzy for Volatility”, which JPCERT/CC has created for extracting known malware from memory images and utilises for analysis operations. Malware Detection in Memory Forensics To judge if a file type malware sample is a known kind, the easiest and fastest way is to check the hash value (e.g. MD5 or SHA 256) of the...
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A shortcut file, also referred to as a shell link, is a system to launch applications or to allow linking among applications such as OLE. As we introduced in a previous blog post “Asruex: Malware Infecting through Shortcut Files”, shortcut flies are often used as a means to spread malware infection. Generally, shortcut files contain various types of information including the dates and environment that the shortcut file was created....
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JPCERT/CC has been observing malicious shortcut files that are sent as email attachments to a limited range of organisations since around October 2015. When this shortcut file is opened, the host will be infected with malware called “Asruex”. The malware has a remote controlling function, and attackers sending these emails seem to attempt intruding into the targets’ network using the malware. According to a blog article by Microsoft, the malware...
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Hello all, this is Shusei Tomonaga again. Generally speaking, malware analysis begins with classifying whether it is known malware or not. In order to make comparison with the enormous number of known malware samples in the database in a speedy manner, hash values are used, derived by performing hash functions to the malware sample. Among the different hash functions, traditional ones such as MD5 and SHA1 derive totally different hash...
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Hello again, this is Shusei Tomonaga from the Analysis Center. In Windows OS, various commands (hereafter “Windows commands”) are installed by default. However, what is actually used by general users is just a small part of it. On the other hand, JPCERT/CC has observed that attackers intruding into a network also use Windows commands in order to collect information and/or to spread malware infection within the network. What is worth...
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Hello again – this is Shusei Tomonaga from Analysis Center. This blog entry is to introduce “apt17scan.py” created by JPCERT/CC to detect certain malware used in targeted attacks, and to extract its configuration information. It is a plugin for the Volatility Framework (hereinafter “Volatility”), a memory forensics tool. My colleague Yuu Nakamura and I had the honour to introduce this at CODE BLUE 2015, an international conference for information security...
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Hi, it’s Shusei Tomonaga again from the Analysis Center. JPCERT/CC has confirmed several attack cases around May 2015, which attempt to steal information of computers leveraging specific network devices featuring VPN server functions. The target of the reconnaissance varies from installed software to keylogs, and it is presumed that the attacker has aimed to steal such information from computers which attempt to login to VPN servers through altered login pages....
