Ahnlab Magniber Decrypt

AhnLab 보안 제품과 서비스 구성을 한. (Magniber) 랜섬웨어, 크립트엑스엑스엑스(CryptXXX) 3.x 버전, 2.x 버전, 나부커(Nabucur), 테슬라크립트(TeslaCrypt)의 일부이며, 신∙변종. Clone via HTTPS Clone with Git or checkout with SVN using the repository’s web address. At the end of March 2018, security researchers from AhnLab released multiple decryptors for different types of Magniber virus. The recovery tool functions based on an encryption bug that was left out by hackers. Below you can see the table showing which versions of Magniber. How to remove Magniber virus and restore encrypted files. This article is dedicated to ransomware called Magniber which gets onto customers' machines around the world, and encrypts their files. Here we've assembled full info on Magniber's essence, and the deletion of Magniber from your system.

Magniber is a fresh ransomware variant being increasingly spread by the Magnitude Exploit Kit. It seems to be a descendant of the Cerber Ransomware.

Although many elements of the Magniber Ransomware differ from Cerber, the payment portal and the documents} it encrypts are almost identical.

Magniber means Magnitude + Cerber.

Making use of malvertisements on websites operated by hackers, the Magnitude exploit kit tries to employ an IE vulnerability to download the Magniber Ransomware.

Cerber has almost gone silent since mid-September, having no significant distribution activities. All of a sudden, the Magnitude exploit kit, the last tool Cerber operators used to distribute their virus, starts spreading new ransomware which includes similar payment portal as Cerber.

A distinctive characteristic of the Magniber virus is the way a victim logs into the payment portal. In most cases, a ransomware will generate a special user ID. This ID is then included in the ransom notes and users should use it to log in to their payment website on the TOR network.

Magniber changes this scheme. Rather than asking the user to login in with the ID, criminals use this ID as a subdomain on the payment site. For instance, a ransom note will provide such link: http://asd10iv3t53s1xff7p8.bankme.date where the subdomain reflects the user’s ID – asd10iv3t53s1xff7p8.

During the first start, Magniber identifies the Windows system language. It cancels all further activities and will not encrypt any files if the language is not Korean. On the contrary, if victim’s machine uses Korean language, the virus will create a special user ID to be used in processing the future payments as outline above.

After that, the actual file encryption process starts. When encrypting files, this virus appends a specific extension. For now, malware researchers have found two file extensions being used based on the executable. These are: .kgpvwnr and .ihsdj.

During the encryption process, Magniber is going to generate a ransom note called READ_ME_FOR_DECRYPT_(ID).txt in each folder. There are links to the payment portal in Magniber’s ransom notes. The payment portal offers detailed info on how to buy Bitcoins and how to pay the ransom.

As soon as a user sends a payment to the mentioned Bitcoin address, his/her payment is going to be presented in the Payments area of the decryptor website. After several transaction confirmations, this website gives a download link for the user’s exclusive decryptor. The present ransom amount is 0.2 BTC, which increases two times in five days.

Victims have an opportunity to speak to the ransomware author using the support page included on the payment portal.

Finally, victims have an opportunity to decrypt a single file to verify that ransomware author can decrypt their data.

For anyone who is infected with this ransomware, we have a removal and decryption guide below.

Automatic removal of Magniber Ransomware

The benefits of using the automatic security suite to get rid of this infection are obvious: it scans the entire system and detects all potential fragments of the virus, so you are a few mouse clicks away from a complete fix.

  1. Download and install recommended malware security suite
  2. Select Start Computer Scan feature and wait until the utility comes up with the scan report. Proceed by clicking on the Fix Threats button, which will trigger a thorough removal process to address all the malware issues compromising your computer and your privacy.

Restore files locked by Magniber Ransomware

new Locky variant aka Magniber Ransomware represents a unique category of malicious software whose attack surface reaches beyond the operating system and its components, which is why removing the virus itself is a part of the fix only. As it has been mentioned, it encrypts one’s personal information, so the next phase of the overall remediation presupposes reinstating the files that will otherwise remain inaccessible.

  • Launch data recovery software

    Similarly to the rest of its fellow-infections, Magniber Ransomware most likely follows an operational algorithm where it erases the original versions of the victim’s files and actually encrypts their copies. This peculiarity might make your day, because forensics-focused applications like Data Recovery Pro are capable of restoring the information that has been removed. As the virus further evolves, its modus operandi may be altered – in the meanwhile, go ahead and try this.

  • Take advantage of Volume Shadow Copy Service

    This technique is based on using the native backup functionality that’s shipped with Windows operating system. Also referred to as Volume Snapshot Service (VSS), this feature makes regular backups of the user’s files and keeps their most recent versions as long as System Restore is on. Magniber Ransomware hasn’t been found to affect these copies therefore the restoration vector in question is strongly recommended. The two sub-sections below highlight the automatic and manual workflow.

  • a) Use Shadow Explorer

    Shadow Explorer is an applet that provides an easy way of retrieving previous versions of files and folders. Its pro’s include an intuitive interface where the computer’s entire file hierarchy is displayed within one window. Just pick the hard disk volume, select the object or directory to be restored, right-click on it and choose Export. Follow the app’s prompts to get the job done.

  • b) Use file properties

    Essentially, what the above-mentioned Shadow Explorer tool does is it automates the process that can otherwise be performed manually via the Properties dialog for individual files. This particular approach is more cumbrous but just as effective as its software-based counterpart, so you can proceed by right-clicking on a specific file, which has been encrypted by Magniber Ransomware, and selecting Properties in the context menu. The tab named Previous Versions is the next thing to click – it displays available versions of the file by date of the snapshot creation. Pick the latest copy and complete the retrieval by following the prompts.

  • Data backups work wonders

    Ransomware like Magniber Ransomware isn’t nearly as almighty and destructive in case you run regular file backups to the cloud or external data media. The virus itself can be completely removed in a matter of minutes, and the distorted information can then be just as easily recovered from the backup. Luckily, this is a growing trend, so ransom Trojans are hopefully going to become less subversive in the near future.

Ahnlab magniber decrypt v4.1

Verify thoroughness of the removal

Ahnlab Magniber Decrypt V4

Having carried out the instructions above, add a finishing touch to the security procedure by running an additional computer scan to check for residual malware activity

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Release Date : 2018-12-27 16:13:41 Update Date : 2018-12-27 16:25:19 Author :

Ahnlab Magniber Decrypt V4.1


【Abstract】Magniber is a ransomware distributed by Magnitude’s operator. The latest version of Magniber has been upgraded in a comprehensive way in terms of encryption method, infected object, etc. This article comprehensively analyzes the latest version of Magniber from the perspectives of its attack process, harm, behavior analysis, comparison with earlier version, security protection measures, etc.

Magniber is a ransomware distributed by Magnitude's operator. The latest version of Magniber has been upgraded in a comprehensive way in terms of encryption method, infected object, etc. This article comprehensively analyzes the latest version of Magniber from the perspectives of its attack process, harm, behavior analysis, comparison with earlier version, security protection measures, etc.

Magnitude EK is a long-lasting browser exploit tool that has been very active since its inception in 2013, and through which multiple ransomware packages have been distributed - from Cerber to Magniber, GangCrab, etc. The tool has been one of the favorite tools for ransomware users worldwide.

Magniber is a ransomware distributed by Magnitude's operator. The original version of Magniber mainly targets South Korea and has a relatively simple encryption method. The latest version of Magniber has been upgraded in a comprehensive way, and can infect many Asian countries including China, and has a quite different encryption method. The latest version of Magniber exploits the CVE-2018-8174 VBScript engine memory corruption vulnerability of Internet Explorer (please refer to related article for vulnerability analysis). This article comprehensively analyzes the latest version of Magniber from the perspectives of its attack process, harm, behavior analysis, comparison with earlier version, security protection measures, etc.

Magniber's attack process is mainly divided into the following stages:

Magnigate’s 302 redirection

A Base64 obfuscated JavaScript is used to launch Magnitude’s landing page

A Base64 encoded VBScript is used, the main functionality of which is to determine whether the CVE-2018-8174 vulnerability exists. If the vulnerability exists, the shellcode is executed and the payload (the first dll) is downloaded

The dll loader unpacks the Magniber’s core dll and injects it into a process

The core dll completes the proceses of local file traversal and encryption for ransom

Let's first take a look at Magniber's traffic view[1], as shown below:


(The image is from Malwarebytes [1])


It can be found that after Magnigate's 302 redirection, the Base64 encoded and obfuscated JavaScript and VBScript are called. The original JavaScript is as follows:

The decoded JavaScript is as follows:

The decoded VBScript main function is as follows (for detailed information about VBScript, please refer to another article 'Microsoft VBScript Engine Remote Code Execution Vulnerability (CVE-2018-8174) Analysis Report'):

As can be seen from the VBScript, the functionality implemented by the script is to judge whether the VBScript UAF vulnerability CVE-2018-8174 exists. If the vulnerability exists, the vulnerability is triggered and the type confusion is used to save and execute the constructed Shellcode by constructing the VirtualProtect structure. The shellcode executed is as follows:

In terms of functionality, the Shellcode is a simple downloader which will download the obfuscated load dynamic link library (load.dll), decode it with the key through XOR operation, and deploy it.

The downloaded load dynamic link library (load.dll) is still not the core of Magniber ransomware. The main functionality of load.dll is to load the next stage program, extract Magniber's core DLL (core.dll), and inject the core DLL into a process. Both DLLs, with Reflective Loader stub, load themselves into a current process using the Reflective DLL injection technique. For the Reflective DLL Injection technique, please refer to [2].


After the core DLL is loaded into the process, it will soon be found that files (including compressed files, Office documents, scripts, images, videos, etc.) in all directories will be encrypted and added with the extension .dyaaghemy, and a README.txt file (roughly means you need to pay a ransom to decrypt the files) will be placed in the current directory, as shown below:



The link in the given README.txt points to an onion web interface that is unique to each victim and similar to many other ransomware pages:



(The image is from malwarebytes[1])


Each file encrypted by the latest version of Magniber has a .dyaaghemy extension, and each file is encrypted with a unique key. The encrypted content is completely garbled, indicating that a stream cipher or a blockchain cipher (probably AES encryption in CBC mode) is adopted by the attacker. The effect of Magniber infection is as follows (take php file as an example):



The latest version of the Magniber contains 2 dlls, of which 72fce87a9766a8c09ed844564adc75 is just the next stage loader that unpacks Magniber's core DLL (19599cad1bbca18ac6473e64710443b7) and injects it into a process.

4.1 Load dll (load.dll) Behavior Analysis


Load.all code is relatively simple, and its main functionality can be understood through static analysis. The entry function of load.dll is as follows:



After getting into the core processing function, we can see that it carries out a process injection, as shown below:




Next, open the local notepad and write the data:



Query current process information:



Get the information about the module loaded by the current process:


4.2 Core dll (core.dll) Behavior Analysis

4.2.1 Core.dll Overall Structure

4.2.2 Core.dll Specific Analysis

Core.dll Entry:



Follow up the execfunc() function. If there is a function pointer in the corresponding position, execute:



Follow up the sub_10008768 function to get into the core processing function main().




It first judges the system language, if not Chinese (Hong Kong), Chinese (Macau), Chinese (Simplified), Chinese (Singapore), Chinese (Taiwan), Korean (Korean), Malay (Malaysia), it directly call the function 1000 to exit. Please refer to the link [3] for specific language ID.




Then a series of operations on the memory layout are carried out, the result is as follows:




Next, the advapi32.dll is loaded to clear the memory area, extend the environment variable string, and replace the environment variable string % PUBLIC% with the current user-defined value:




Next, call the 4FA8 function to create the mutex dyaaghemy (the extension of the encrypted files):



Call GetTickCount to get 19 random strings:





Copy the URL and other information to get the disk drive letter:




Get disk information:



Encrypt the primary and logical disks:



Call 59F7 in 64C4, compare it with the folder under the C drive, and encrypt the disk files:



Traverse the file, determine whether the file is an executable file and other attribute values, and obtain a random value to prepare for the encryption operation:



Use the encryption function provided by the system to generate the encryption key:



File encryption:



Generate ransom information:




Then operate the registry and execute other commands:




After all the work is completed, a data pack is sent to report completion:



For analysis of earlier version, please refer to link [4]. Compared with the earlier version, the new version mainly has the following changes:

(1) A lot of code obfuscation techniques are adopted

Compared with previous version of Magniber, a lot of effort has been put into code obfuscation, and the code is obfuscated via a variety of different techniques. First of all, API functions are now dynamically retrieved by their checksums:



Dynamic retrieval: a function pointer is obtained by searching the export table of the currently loaded dll. In addition, some of the parameters for the calls are dynamically calculated and junk code is added in between the operations. A string that is supposed to be loaded is scattered through several variables:




(2)More countries are targeted

The previous version of Magniber only targets South Korea, the new version of Magniber is aimed at more countries. The supported languages are Chinese (Simplified, Taiwan, Singapore), Korean (Korean), Malay (Malaysia), etc.


(3) File encryption

File encryption of the earlier version depends on the AES key downloaded from the CnC server (if not available, it returns to a hard-coded key, in which case file encryption is relatively easy). This time, Magniber comes with a public RSA key of the attackers that makes it fully independent from the Internet connection during the encryption process. This key is used for protecting the unique AES keys used to encrypt files.


Extensions used

.fprgbk; .ihsdj; .kgpvwnr; .vbdrj; .skvtb; .vpgvlkb; .dlenggrl; .dxjay; .fbuvkngy; .xhspythxn; .demffue; .mftzmxqo; .qmdjtc; .wmfxdqz; .ndpyhss; . dyaaghemy

.fprgbk, .ihsdj, .kgpvwnr, .vbdrj, .skvtb, .vpgvlkb, .dlenggrl, .dxjay, .fbuvkngy, .xhspythxn, .demffue, .mftzmxqo, .qmdjtc, .wmfxdqz, .ndpyhss, . dyaaghemy

Behavior

File encryption

Distribution method

Exploit CVE-2018-8174 VBScript UAF vulnerability

How to remove

Download and install Reimage [5], Malwaresbytes [6], etc. Restart your computer in safe mode.

How to decrypt

Refer to links [7-8]:

1.http://asec.ahnlab.com/1124

2.https://gist.github.com/evilsocket/b89df665e6d52446e3e353fc1cc44711




1. The spread of Magniber is mainly based on the Internet Explorer's latest VBScript engine memory corruption vulnerability, namely CVE-2018-8174. Therefore, you first need to fix the vulnerability to avoid the harm of the ransomware. Fix suggestions: fix the vulnerability CVE-2018-8174 according to the vendor-provided patch: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8174[9].

2. Deploy an IPS product to block related attacks. HUAWEI has released a signature database to detect CVE-2018-8174, please upgrade to the latest version which can be downloaded at https://isecurity.huawei.com/sec/web/freesignature.do


Reference Links

[1]https://blog.malwarebytes.com/threat-analysis/2018/07/magniber-ransomware-improves-expands-within-asia/

[2]https://github.com/stephenfewer/ReflectiveDLLInjection

[3]https://www.cnblogs.com/wangweixf/archive/2008/08/15/1268537.html

[4]https://blog.malwarebytes.com/threat-analysis/2017/10/magniber-ransomware-exclusively-for-south-koreans/

[5]http://wubingdu.cn/download/ReimageRepair

[6]http://wubingdu.cn/download/mb3-setup

[7]http://asec.ahnlab.com/1124

[8]https://gist.github.com/evilsocket/b89df665e6d52446e3e353fc1cc44711

[9]https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8174

1.Magniberload.dll):

6e57159209611f2531104449f4bb86a7621fb9fbc2e90add2ecdfbe293aa9dfc

2.Magnibercore.dll):

fb6c80ae783c1881487f2376f5cace7532c5eadfc170b39e06e17492652581c2

3.Javascript

https://gist.github.com/malwarezone/62e765a5d238360af68c9ca654cc4513#file-3-vb

4.VBScript

https://gist.github.com/malwarezone/62e765a5d238360af68c9ca654cc4513#file-4-vb


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