Category: Ransomware

Oct 25 2017

BadRabbit: New strain of ransomware hits Russia and Ukraine

BadRabbit is self-propagating and has many similarities to the June 2017 Petya / NotPetya outbreak.

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Oct 24 2017

‘BadRabbit’ Ransomware Burrows Into Russia, Ukraine

This post was researched and written by Christiaan Beek, Tim Hux, David Marcus, Charles McFarland, Douglas McKee, and Raj Samani.

McAfee is currently investigating a ransomware campaign known as BadRabbit, which initially infected targets in Russia and the Ukraine. We are also investigating reports of infected systems in Germany, Turkey, and Bulgaria and will provide updates as more information becomes available. For McAfee product coverage, please see “How McAfee Products Can Protect Against BadRabbit Ransomware.”

When victims visit the following site, a dropper is downloaded:

hxxp://1dnscontrol[dot]com/flash_install.php

After infection, the victim sees the following screen:

The ransomware is currently charging 0.05 Bitcoin; however, there is no confirmation that paying the ransom will result in a decryption key being provided.

A decryption site at the following .onion (Tor) domain displays the time that victims have left before the price goes up:

caforssztxqzf2nm[dot]onion

Files with the following extensions are encrypted:

.3ds.7z.accdb.ai.asm.asp.aspx.avhd.back.bak.bmp.brw.c.cab.cc.cer.cfg.conf.cpp.crt.cs.ctl.cxx.dbf .der.dib.disk.djvu.doc.docx.dwg.eml.fdb.gz.h.hdd.hpp.hxx.iso.java.jfif.jpe.jpeg.jpg.js.kdbx.key .mail.mdb.msg.nrg.odc.odf.odg.odi.odm.odp.ods.odt.ora.ost.ova.ovf.p12.p7b.p7c.pdf.pem.pfx .php.pmf.png.ppt.pptx.ps1.pst.pvi.py.pyc.pyw.qcow.qcow2.rar.rb.rtf.scm.sln.sql.tar.tib.tif.tiff .vb.vbox.vbs.vcb.vdi.vfd.vhd.vhdx.vmc.vmdk.vmsd.vmtm.vmx.vsdx.vsv.work.xls.xlsx.xml.xvd.zip.

The malware starts a command-line with following values:

Cmd /c schtasks /Create /RU SYSTEM /SC ONSTART /TN rhaegal /TR “C:\Windows\system32\cmd.exe /C Start \”\” \”C:\Windows\dispci.exe\” -id 1082924949 && exit”

“/TN rheagal” refers to a system account with the name rhaegal used to create the scheduled task and start the ransomware file dispci.exe. Rhaegal is likely a reference to a dragon from the popular TV show “Game of Thrones.” In fact, three dragon names—Rhaegal, Viserion, and Drogon—are used in relation to the following scheduled tasks:

The malware then uses the following commands to clear security logs and delete the update sequence number (USN) change journal, which is used to recover files, for example:

Cmd /c wevtutil cl Setup & wevtutil cl System & wevtutil cl Security & wevtutil cl Application & fsutil usn deletejournal /D C:

The USN change journal provides a persistent log of all changes made to files on the volume, according to the Microsoft Developer Network. As files, directories, and other NTFS objects are added, deleted, and modified, NTFS enters records into the USN change journal, one for each volume on the computer. Each record indicates the type of change and the object changed. New records are appended to the end of the stream.

We also found a DNS query to ACA807(x)ipt.aol[dot]com, in which the “##” is a two-digit hex number from 00-FF ACA807##.ipt.aol[dot]com.

We created a graph of the events occurring during an infection by one of the BadRabbit samples. The initial binary loads itself into memory and kills the initial process. Further processes drop configuration, services files, and other artifacts used in the attacks. The graph ends with the creation of the preceding scheduled tasks.

Embedded Credentials

One of the samples (579fd8a0385482fb4c789561a30b09f25671e86422f40ef5cca2036b28f99648) seems to contain a list of default credentials with an attempt to brute-force credentials and get the scheduled tasks to execute the ransomware:

  • secret
  • 123321
  • zxc321
  • zxc123
  • qwerty123
  • qwerty
  • qwe321
  • qwe123
  • 111111
  • password
  • test123
  • admin123Test123
  • Admin123
  • user123
  • User123
  • guest123
  • Guest123
  • administrator123
  • Administrator123
  • 1234567890
  • 123456789
  • 12345678
  • 1234567
  • 123456
  • adminTest
  • administrator
  • netguest
  • superuser
  • nasadmin
  • nasuser
  • ftpadmin
  • ftpuser
  • backup
  • operator
  • other user
  • support
  • manager
  • rdpadmin
  • rdpuser
  • user-1
  • Administrator

Game of Thrones Fans?

It is common for attackers to use pop-culture references in their attacks. These attackers seem to have an interest in “Game of Thrones,” with at least three references to the series. Viserion, Rhaegal, and Drogon are names of scheduled tasks. GrayWorm, the name of a “Game of Thrones” commander, is the product name in the binary’s EXIF data.

Detection

There are currently three samples associated with this ransomware campaign, representing the dropper and the main executable. McAfee detects all three:

  • 630325cac09ac3fab908f903e3b00d0dadd5fdaa0875ed8496fcbb97a558d0da
  • 8ebc97e05c8e1073bda2efb6f4d00ad7e789260afa2c276f0c72740b838a0a93
  • 579fd8a0385482fb4c789561a30b09f25671e86422f40ef5cca2036b28f99648

 

The post ‘BadRabbit’ Ransomware Burrows Into Russia, Ukraine appeared first on McAfee Blogs.

Oct 17 2017

Necurs attackers now want to see your desktop

The Necurs botnet is back again, this time spreading a downloader that takes screen grabs of victims’ desktops and reports encountered errors back to the attackers.

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Oct 12 2017

Taiwan Bank Heist and the Role of Pseudo Ransomware

Widespread reports claim the Far Eastern International Bank in Taiwan has become a victim of hacking. The attacks demonstrate the global nature of cybercrime, with the cybercriminals attempting to wire US$60 million to destinations such as Sri Lanka, Cambodia, and the United States. Recent reports from Sri Lanka say that two individuals have been arrested for suspected money laundering after a tip-off from the Bank of Ceylon, which reported a suspicious transfer of $1.2 million from the Far Eastern International Bank.

On Saturday October 7, Far Eastern International Bank reported that it had recovered most of the money and that overall losses could reach $500,000.

How did the attack happen?

Based on the initial intelligence we have received, the first direct interaction with the victim began with spear phishing attacks that contained “backdoor” attachments.

Figures 1 and 2 provide some examples of the attachments.

Figure 1: Spear phishing attachment.

Figure 2: Spear phishing attachment.

When the victim clicks on the link, they are redirected to a malicious site that downloads additional files to the victim’s computer. One example of these malicious sites is hxxps://jobsbankbd.com/maliciousfilename.exe.

This site hosts another backdoor that gives the criminals access to the victim’s system in the bank.

Once the criminals gain access to the systems, our initial analysis reveals that the attackers harvested credentials. This was confirmed by evidence we found in a sample that contained the following credentials from the bank:

  • FEIB\SPUSER14
  • FEIB\scomadmin

These credentials are used to create a scheduled task on the system and monitor the running of endpoint security services. (This does not indicate a problem with the security software, only that the attackers did their research and took measures to take out the security software being run within the bank.) We have notified the security provider, and have provided all of our research to date.

Besides the scheduled task and credentials, we discovered another interesting piece of code. Inside the sample was the resource “IMAGE,” which seemed to be a zip file. Once extracted, we found the file aa.txt. Although this appeared to be a text file, it was really an executable.

The file contains code that scans for the installed languages, especially:

  • 419 (Russian)
  • 422 (Ukrainian)
  • 423 (Belarusian)

If these languages are detected, the file will not run. We have seen this behavior before in ransomware families.

When analyzing the strings of this particular file, we discovered some interesting ones:

  • HERMES 2.1 TEST BUILD, press ok
  • HERMES

When executed, the file proved to be ransomware. However, no note or wallpaper indicated that this was ransomware. After the file finished running, only one thing appeared on the desktop:

Figure 3: The final screen of this pseudo ransomware.

And in every directory a file:

The original Hermes ransomware note points toward this file; but in our case, we saw no note, nor demand for ransom. The Hermes ransomware family surfaced in February:

We suspect that this is another example of pseudo ransomware. Was the ransomware used to distract the real purpose of this attack? We strongly believe so.

Based on our sources, the ransomware attack started in the network when the unauthorized payments were being sent.

Where next?

Clearly this was a very carefully crafted attack, and specifically targeted at one bank. The attackers identified specific individuals to email, and understood the security measures being deployed. Although the samples we identified are now covered by our security products, we urge caution in anyone assuming that “I am protected.” The criminals took their time to understand how the bank works and developed the necessary code to enable them to steal millions. An effective security posture must anticipate such highly skilled attackers.

Because this is related an active law enforcement investigation, we are limiting what information we publicly share and will publish further updates only if that does not conflict with a current investigation.

The post Taiwan Bank Heist and the Role of Pseudo Ransomware appeared first on McAfee Blogs.