Campaign Evolution: Darkleech to Pseudo-Darkleech and Beyond

Posted on by Brad Duncan

In 2015, Sucuri published two blog posts, one in March describing a pseudo-Darkleech campaign targeting WordPress sites, and another about its evolution the following December. Sites compromised by this campaign redirected unsuspecting users to an exploit kit (EK). The Sucuri posts describe patterns in the injected script related to this campaign. Since December 2015, patterns associated with pseudo-Darkleech have continued to evolve. Our blog post today will examine these changes.

However, before we look at the recent developments, we should understand how EKs fit into the overall picture and review the history of Darkleech.

Continue reading "Campaign Evolution: Darkleech to Pseudo-Darkleech and Beyond"

Locky Ransomware Installed Through Nuclear EK

Posted on by Brad Duncan

In February 2016, Unit 42 published detailed analysis of Locky ransomware. We certainly weren’t the only ones who saw this malware, and many others have also reported on it. Since that time, Locky has been frequently noted in various campaigns using malicious spam (malspam) to spread this relatively new strain of ransomware.

When we initially reported on Locky, attackers were distributing the malware using Microsoft Office documents with malicious macros to download and execute the ransomware. Attackers quickly added another tactic, sending e-mails with zip attachments containing malicious Javascript files to accomplish the same goal. However, exploit kits (EKs) have also been used to infect users with Locky from casual web browsing. This activity suggests that there are effectively two paths to Locky: one through malspam and another through EK traffic.

Continue reading "Locky Ransomware Installed Through Nuclear EK"

AceDeceiver: First iOS Trojan Exploiting Apple DRM Design Flaws to Infect Any iOS Device

Posted on by Claud Xiao

We’ve discovered a new family of iOS malware that successfully infected non-jailbroken devices we’ve named “AceDeceiver”.

What makes AceDeceiver different from previous iOS malware is that instead of abusing enterprise certificates as some iOS malware has over the past two years, AceDeceiver manages to install itself without any enterprise certificate at all. It does so by exploiting design flaws in Apple’s DRM mechanism, and even as Apple has removed AceDeceiver from App Store, it may still spread thanks to a novel attack vector.

AceDeceiver is the first iOS malware we’ve seen that abuses certain design flaws in Apple’s DRM protection mechanism -- namely FairPlay -- to install malicious apps on iOS devices regardless of whether they are jailbroken. This technique is called “FairPlay Man-In-The-Middle (MITM)” and has been used since 2013 to spread pirated iOS apps, but this is the first time we’ve seen it used to spread malware. (The FairPlay MITM attack technique was also presented at the USENIX Security Symposium in 2014; however, attacks using this technique are still occurring successfully.)

Continue reading "AceDeceiver: First iOS Trojan Exploiting Apple DRM Design Flaws to Infect Any iOS Device"

Digital Quartermaster Scenario Demonstrated in Attacks Against the Mongolian Government

Posted on by Josh Grunzweig

Unit 42 has collected multiple spear phishing emails, weaponized document files, and payloads that targeted various offices of the Mongolian government during the time period of August 2015 and February 2016. The phishing emails and document files leveraged a variety of geopolitically sensitive subject matters as attractive lures, such as events in Beijing, the Dalai Lama, North Korea relations, the Zika virus, and various legitimate appearing announcements. As we began to analyze and tear down the various samples we collected, we found significant overlaps with previously reported and documented adversary groups, attack campaigns, and their toolsets, exemplifying the concept of the Digital Quartermaster.

Continue reading "Digital Quartermaster Scenario Demonstrated in Attacks Against the Mongolian Government"

PowerSniff Malware Used in Macro-based Attacks

Posted on by Josh Grunzweig

Introduction

The concept of file-less malware is not a new one. Families like Poweliks, which abuse Microsoft’s PowerShell, have emerged in recent years and have garnered extensive attention due to their ability to compromise a system while leaving little or no trace of their presence to traditional forensic techniques.

System administrators have lauded the power and versatility of PowerShell since version 2.0’s integration into Windows 7. Unfortunately, with such versatility comes the opportunity for abuse, specifically surrounding the capability to write directly into memory of the host OS.

Typically, file-less malware has been observed in the context of Exploit Kits such as Angler. Palo Alto Networks has observed a recent high-threat spam campaign that is serving malicious macro documents used to execute PowerShell scripts which injects malware similar to the Ursnif family directly into memory. We call the malware PowerSniff. Continue reading "PowerSniff Malware Used in Macro-based Attacks"

Palo Alto Networks Researcher Discovers Critical IE Vulnerability

Posted on by ryanolson

Palo Alto Networks researcher Hui Gao was credited with the discovery of a new critical Microsoft vulnerability affecting Internet Explorer (IE) versions 9, 10 and 11. This vulnerability is covered in Microsoft’s March 2016 Security Bulletin and documented in Microsoft Security Bulletin MS16-023. Continue reading "Palo Alto Networks Researcher Discovers Critical IE Vulnerability"

Banload Malware Affecting Brazil Exhibits Unusually Complex Infection Process

Posted on by Anthony Kasza

As previously discussed by Unit 42, banking Trojans have been targeting Brazilian systems for years given the popularity of online banking services in the country. Recently, we analyzed a handful of samples targeting Brazilian systems that exhibited a unique and complex multi-stage loading process. Antivirus detection names for this malware typically are detected as generic named families or “Banload”.

In this blog post, I’ll share details of the complexity of this Trojan’s installation process, which involves a series of archive downloads, process injections and executable installations, all orchestrated by an encrypted AutoIt script.

Please Note: This blog focuses specifically on the complexities of a malware infection process, but not on the impact of the malware or it’s other functionalities.

For those looking for a higher-level look at some of our recent research, please enjoy one of these options: Continue reading "Banload Malware Affecting Brazil Exhibits Unusually Complex Infection Process"

New OS X Ransomware KeRanger Infected Transmission BitTorrent Client Installer

Posted on by Claud Xiao

On March 4, we detected that the Transmission BitTorrent client installer for OS X was infected with ransomware, just a few hours after installers were initially posted. We have named this Ransomware “KeRanger.” The only previous ransomware for OS X we are aware of is FileCoder, discovered by Kaspersky Lab in 2014. As FileCoder was incomplete at the time of its discovery, we believe KeRanger is the first fully functional ransomware seen on the OS X platform.

Attackers infected two installers of Transmission version 2.90 with KeRanger on the morning of March 4. When we identified the issue, the infected DMG files were still available for downloading from the Transmission site (hxxps://download.transmissionbt.com/files/Transmission-2.90[.]dmg) Transmission is an open source project. It’s possible that Transmission’s official website was compromised and the files were replaced by re-compiled malicious versions, but we can’t confirm how this infection occurred.

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Figure 1 KeRanger hosted in Transmission's official website

The KeRanger application was signed with a valid Mac app development certificate; therefore, it was able to bypass Apple’s Gatekeeper protection. If a user installs the infected apps, an embedded executable file is run on the system. KeRanger then waits for for three days before connecting with command and control (C2) servers over the Tor anonymizer network. The malware then begins encrypting certain types of document and data files on the system. After completing the encryption process, KeRanger demands that victims pay one bitcoin (about $400) to a specific address to retrieve their files. Additionally, KeRanger appears to still be under active development and it seems the malware is also attempting to encrypt Time Machine backup files to prevent victims from recovering their back-up data.

Palo Alto Networks reported the ransomware issue to the Transmission Project and to Apple on March 4. Apple has since revoked the abused certificate and updated XProtect antivirus signature, and Transmission Project has removed the malicious installers from its website. Palo Alto Networks has also updated URL filtering and Threat Prevention to stop KeRanger from impacting systems. Continue reading "New OS X Ransomware KeRanger Infected Transmission BitTorrent Client Installer"

New Malware 'Rover' Targets Indian Ambassador to Afghanistan

Posted on by Vicky Ray

On December 24, 2015, Unit 42 identified a targeted attack, delivered via email, on a high profile Indian diplomat, an Ambassador to Afghanistan. The body and content of the email suggest that it was crafted and spoofed to look like it was sent by the current Defence Minister of India, Mr. Manohar Parrikar, commending the Ambassador on his contributions and success.

India has been a key nation in building and funding Afghanistan’s infrastructure and economic development, which includes setting up iron ore mines, steel plants, power plants and transportation systems, helping reconstruct the Salma Dam and constructing a new Parliament Complex for the Afghan Government.

Given India’s significant contributions to the development of Afghanistan, it is likely that there may be groups or nations who would be interested in tracking and spying on key individuals who officially represent India in Afghanistan. Continue reading "New Malware 'Rover' Targets Indian Ambassador to Afghanistan"

KeyBase Threat Grows Despite Public Takedown: A Picture is Worth a Thousand Words

Posted on by Jeff White

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In June 2015, Unit 42 reported on a keylogger malware family known as KeyBase, which had first appeared in February 2015. The author has since taken down its website and supposedly ceased selling the software, while also renouncing the tool’s use for any malicious purposes. However, as of this writing, the software is still readily available for download with minimal effort on multiple websites. What’s more, while development of KeyBase appears to have stopped, the usage of this malware has increased significantly since June. In our initial report, we identified approximately 1,500 sessions carrying KeyBase and approximately six months later we have seen over 4,900 different samples and 44,200 sessions within Palo Alto Networks AutoFocus. Continue reading "KeyBase Threat Grows Despite Public Takedown: A Picture is Worth a Thousand Words"

Pirated iOS App Store’s Client Successfully Evaded Apple iOS Code Review

Posted on by Claud Xiao

Apple’s official iOS App Store is well known for its strict code review of any app submitted by a developer. This mandatory policy has become one of the most important mechanisms in the iOS security ecosystem to ensure the privacy and security of iOS users. But we recently identified an app that demonstrated new ways of successfully evading Apple’s code review. This post discusses our findings and potential security risks to iOS device users.

The app we identified is named “开心日常英语 (Happy Daily English),” and it has since been removed by Apple from the App Store. This app was a complex, fully functional third party App Store client for iOS users in mainland China. We also discovered enterprise signed versions of this application elsewhere in the wild. We had not identified any malicious functionality in this app, and as such we classified it as Riskware and have named it ZergHelper.

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Figure 1: "Happy Daily English" available in the App Store

ZergHelper presents several security risks, include the following: Continue reading "Pirated iOS App Store’s Client Successfully Evaded Apple iOS Code Review"

New Android Trojan “Xbot” Phishes Credit Cards and Bank Accounts, Encrypts Devices for Ransom

Posted on by Cong Zheng

We recently discovered 22 Android apps that belong to a new Trojan family we’re calling “Xbot”. This Trojan, which is still under development and regularly updated, is already capable of multiple malicious behaviors. It tries to steal victims’ banking credentials and credit card information via phishing pages crafted to mimic Google Play’s payment interface as well as the login pages of 7 different banks’ apps. It can also remotely lock infected Android devices, encrypt the user’s files in external storage (e.g., SD card), and then ask for a U.S. $100 PayPal cash card as ransom. In addition, Xbot will steal all SMS messages and contact information, intercept certain SMS messages, and parse SMS messages for mTANs (Mobile Transaction Authentication Number) from banks. Continue reading "New Android Trojan “Xbot” Phishes Credit Cards and Bank Accounts, Encrypts Devices for Ransom"

Locky: New Ransomware Mimics Dridex-Style Distribution

Posted on by Brandon Levene

Ransomware persists as one of the top crimeware threats thus far into 2016. While the use of document-based macros for ransomware distribution remains relatively uncommon, a new family calling itself "Locky" has borrowed the technique from the eminently successful Dridex to maximize its target base. We first learned of Locky through Invincea and expanded on qualifying this threat with the help of PhishMe. Locky has also gained enough traction to find its way onto Dynamoo’s Blog and Reddit.

Using Palo Alto Networks AutoFocus, Unit 42 observed over 400,000 individual sessions containing the Bartallex macro downloader, which in turned dropped Locky ransomware onto victim machines. Researchers suspect there is a link between the Dridex botnet affiliate 220 and Locky due to similar styles of distribution, overlapping filenames, and an absence of campaigns from this particularly aggressive affiliate coinciding with the initial emergence of Locky. This blog post explores this threat further and offers recommendations on mitigating its impact. Continue reading "Locky: New Ransomware Mimics Dridex-Style Distribution"

A Look Into Fysbis: Sofacy’s Linux Backdoor

Posted on by Bryan Lee

Introduction

The Sofacy group, also known as APT28 and Sednit, is a fairly well known cyber espionage group believed to have ties to Russia. Their targets have spanned all across the world, with a focus on government, defense organizations and various Eastern European governments. There have been numerous reports on their activities, to the extent that a Wikipedia entry has even been created for them.

From these reports, we know that the group uses an abundance of tools and tactics, ranging across zero-day exploits targeting common applications such as Java or Microsoft Office, heavy use of spear-phishing attacks, compromising legitimate websites to stage watering-hole attacks, and targeting over a variety of operating systems – Windows, OSX, Linux, even mobile iOS. Continue reading "A Look Into Fysbis: Sofacy’s Linux Backdoor"

NanoCoreRAT Behind an Increase in Tax-Themed Phishing E-mails

Posted on by Anthony Kasza

It seems every mainstream news event or holiday has an accompanying phishing campaign. Opportunistic actors hoping to capitalize on the public's attention are often seen sending phishing e-mails with themes related to the news or the season..

It happened this last holiday season and will likely continue to occur as long as email is around.

Unsurprisingly, as we near the U.S. deadline for filing our income taxes, Palo Alto Networks researchers have seen an increase in phishing emails specifically related to taxes. This blog details some recent trends we have been able to identify. Palo Alto Networks noticed both executable attachments and Microsoft Word documents with macros designed to download and execute files. Continue reading "NanoCoreRAT Behind an Increase in Tax-Themed Phishing E-mails"

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