The Week in Review from Stamus Labs

Welcome to the weekly threat detection update report from Stamus Networks. Each week, you will receive this email with a summary of the updates.

Current Stamus Threat Intelligence (STI) release version: 1120

This week, in addition to daily ruleset and IOC updates, we provided Stamus Security Platform customers with the following improved defense(s):

New threat detection(s) added [1]: 4 (PshellBkdr, Specula, Mandrake, Zebrocy)
Major changes to detections(s) [2]: 477
Updated threat detection(s) [3]: 514

Note: a "method" as referenced below, is a discrete detection vector for a given threat.

New Threat(s) Detected

The following detections were added to your Stamus Security Platform (SSP) this past week:

PshellBkdr (Backdoor)

Recently, while investigating a new variant[1] of Zloader/SilentNight[2], an unknown Powershell backdoor and VBS downloader was uncovered. The malware was potentially utilized alongside the new Zloader variant, which CISA publicly linked to BlackBasta[3]. The Powershell backdoor appears to have been constructed to further access via recon activity and to deploy other malware samples including Zloader. Medium

Total number of detection methods: 1
Kill chain phase(s): command and control
MITRE ATT&CK: T1071

Specula (Offensive Tools)

Specula at its core is a C2 framework that operates via the Outlook home page feature. This is not anything specifically new, as other tooling (namely Ruler) exposes the functionality to create a home page that can attack this vector. The ability to abuse the Outlook home page was reported and listed as CVE-2017-11774. With that being the case, why are we releasing tooling related to the Outlook home page attack in 2024?

The Outlook home page was thought to have been patched in Knowledge Bases (KBs) listed under https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2017-11774. After the KB is installed, the UI elements related to Outlook's home page will be gone. This leads one to believe the associated functionality has been removed. Unfortunately, the Registry values that would have been set when the removed UI elements were used still get used by Outlook, even in current Office 365 installs. Trustedsec

Total number of detection methods: 2
Kill chain phase(s): command and control
MITRE ATT&CK: T1071

Zebrocy (Trojan)

Zebrocy is a Trojan that has been used by APT28 since at least November 2015. The malware comes in several programming language variants, including C++, Delphi, AutoIt, C#, VB.NET, and Golang. MITRE

Zebrocy - CERT-UA | Zebrocy - Malpedia |

Total number of detection methods: 32
Kill chain phase(s): command and control, delivery, actions on objectives
MITRE ATT&CK: T1587

Mandrake (Data Theft)

Mandrake is a sophisticated Android espionage platform that has been active in the wild since at least 2016. Mandrake is very actively maintained, with sophisticated features and attacks that are executed with surgical precision.

Mandrake has gone undetected for several years by providing legitimate, ad-free applications with social media and real reviews to back the apps. The malware is only activated when the operators issue a specific command. MITRE

Mandrake - Securelist | Mandrake - Malpedia |

Total number of detection methods: 19
Kill chain phase(s): command and control
MITRE ATT&CK: T1041

Major Detection Changes

The following detections were updated this past week with changes to kill chain phase(s) or MITRE ATT&CK tactic(s)/technique(s):

APT35 (APT)

Magic Hound is an Iranian-sponsored threat group that conducts long term, resource-intensive cyber espionage operations, likely on behalf of the Islamic Revolutionary Guard Corps. They have targeted U.S. and Middle Eastern government and military personnel, academics, journalists, and organizations such as the World Health Organization (WHO), via complex social engineering campaigns since at least 2014. MITRE

Added kill chain phase(s): delivery
Previously supported kill chain phase(s): command and control, delivery
MITRE ATT&CK added: T1566
Previously existing MITRE ATT&CK: T1041, T1071, T1587, T1566, T1583
Methods added: 27

ClearFake (Exploit Kit)

There are several malicious fake updates campaigns being run across thousands of compromised websites. This campaign appears to have started around July 19th, 2023. Based on a search on PublicWWW of the injection base64 there are at least 434 infected sites. The name is a reference to the majority of the Javascript being used without obfuscation. One noticeable difference from SocGholish is that there appears to be no tracking of visits by IP or cookies. As an analyst you can you go back to the compromised site over and over coming from the same IP and not clearing your browser cache. This also means the site owner is more likely to see the infection as well. When a user visits a compromised website with ClearFake, the page initially loads as normal before the whole page is taken over by a call to action to update Chrome.

On the index page of the compromised site there is a Javascript injection. The Javascript is base64 encoded. Presumably this is a dynamic injection and will change over time to reflect the new host for the initial payload. On the index page of the compromised site there is a Javascript injection. The Javascript is base64 encoded. Presumably this is a dynamic injection and will change over time to reflect the new host for the initial payload. The second web call returns a Javascript that creates an iframe to house the fake update UI. The iframe src is set to a Keitaro endpoint. The response from the Keitaro endpoint is the foundation for the HTML to be rendered within the iframe.

ClearFake Malware Analysis

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): command and control, exploitation
MITRE ATT&CK added: T1189
Previously existing MITRE ATT&CK: T1071, T1189
Methods added: 9

Fake Browser (Trojan)

Attackers are utilizing hacked web sites that promote fake browser updates to infect targets with banking trojans. In some cases, post exploitation toolkits are later executed to encrypt the compromised network with ransomware.

Between May and September 2019, FireEye has conducted multiple incident response cases where enterprise customers were infected with malware through fake browser updates.

Hacked sites would display these "fakeupdates" through JavaScript alerts that state the user is using an old version of a web browser and that they should download an offered "update" to keep the browser running "smoothly and securely".

bleepingcomputer

Added kill chain phase(s): exploitation, command and control
Previously supported kill chain phase(s): delivery, exploitation, command and control
MITRE ATT&CK added: T1189
Previously existing MITRE ATT&CK: T1189
Methods added: 21

Keitaro (Phishing)

Cyber criminals violated the law TDS (Traffic Direction System) platform Keitaro and used it to redirect them users in exploit kits RIG and Fallout in order to infect them with malicious software.

TDS platforms are designed for redirection of users in particular sites. Legitimate TDS platforms, such as Keitaro, are mainly used by individuals and companies that want to advertise services or their products. Platforms drive users to the pages that companies want, targeting specific customers and promoting an ad campaign. techbizweb

Added kill chain phase(s): exploitation
Previously supported kill chain phase(s): exploitation, delivery, command and control
Methods added: 1

Lumma (Data Theft)

Lumma is an information stealer written in C, sold as a Malware-as-a-Service by LummaC on Russian-speaking underground forums and Telegram since at least August 2022. Lumma's capabilities are those of a classic stealer, with a focus on cryptocurrency wallets, and file grabber capabilities. Malpedia

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): actions on objectives, command and control, installation
MITRE ATT&CK added: T1071
Previously existing MITRE ATT&CK: T1005, T1071, T1573
Methods added: 87

Malvertising Domain (Phishing)

The MS-ISAC has recently observed an increase in malware that is most often disseminated through malvertising. Malvertising, or malicious advertising, is the use of online, malicious advertisements to spread malware and compromise systems. Generally this occurs through the injection of unwanted or malicious code into ads. Malicious actors then pay legitimate online advertising networks to display the infected ads on various websites, exposing every user visiting these sites to the potential risk of infection. Generally, the legitimate advertising networks and websites are not aware they are serving malicious content. CIS

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): command and control
Methods added: 27

NetSupport RAT (RAT)

Remote Access Trojans are programs that provide the capability to allow covert surveillance or the ability to gain unauthorized access to a victim PC. Remote Access Trojans often mimic similar behaviors of keylogger applications by allowing the automated collection of keystrokes, usernames, passwords, screenshots, browser history, emails, chat lots, etc. Remote Access Trojans differ from keyloggers in that they provide the capability for an attacker to gain unauthorized remote access to the victim machine via specially configured communication protocols which are set up upon initial infection of the victim computer. This backdoor into the victim machine can allow an attacker unfettered access, including the ability to monitor user behavior, change computer settings, browse and copy files, utilize the bandwidth (Internet connection) for possible criminal activity, access connected systems, and more. Malwarebytes

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): actions on objectives, command and control, exploitation, installation
MITRE ATT&CK added: T1105
Previously existing MITRE ATT&CK: T1587, T1105
Methods added: 2

Parrot TDS (Trojan)

Parrot TDS acts as a gateway for further malicious campaigns to reach potential victims. In this particular case, the infected sites’ appearances are altered by a campaign called FakeUpdate (also known as SocGholish), which uses JavaScript to display fake notices for users to update their browser, offering an update file for download. The file observed being delivered to victims is a remote access tool. Avast

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): command and control, delivery
Methods added: 6

RAT Generic (RAT)

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): installation, command and control, actions on objectives, delivery
MITRE ATT&CK added: T1573
Previously existing MITRE ATT&CK: T1071, T1041, T1573
Methods added: 3

SideWinder (APT)

An actor mainly targeting Pakistan military targets, active since at least 2012. We have low confidence that this malware might be authored by an Indian company. To spread the malware, they use unique implementations to leverage the exploits of known vulnerabilities (such as CVE-2017-11882) and later deploy a Powershell payload in the final stages. Malpedia

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): command and control, delivery, actions on objectives
Methods added: 176

SocGholish (Social Engineering)

It leverages compromised websites and performs some of the most creative fingerprinting checks we’ve seen, before delivering its payload (NetSupport RAT). Malwarebytes

Added kill chain phase(s): command and control
Previously supported kill chain phase(s): command and control, exploitation, delivery, reconnaissance, actions on objectives
MITRE ATT&CK added: T1189
Previously existing MITRE ATT&CK: T1027, T1189, T1587
Methods added: 3

TA4903 (APT)

An advanced persistent threat (APT) is a stealthy computer network threat actor, typically a nation state or state-sponsored group, which gains unauthorized access to a computer network and remains undetected for an extended period. In recent times, the term may also refer to non-state sponsored groups conducting large-scale targeted intrusions for specific goals.

Such threat actors' motivations are typically political or economic. To date, every major business sector has recorded instances of attacks by advanced actors with specific goals seeking to steal, spy or disrupt. These include government, defense, financial services, legal services, industrial, telecoms, consumer goods, and many more. Some groups utilize traditional espionage vectors, including social engineering, human intelligence and infiltration to gain access to a physical location to enable network attacks. The purpose of these attacks is to place custom malicious code on one or multiple computers for specific tasks.

Source: Wikipedia

Added kill chain phase(s): delivery
Previously supported kill chain phase(s): delivery
Methods added: 21

TA582 (APT)