BLACK FRIDAY: 2-for-1 offer NOVEMBER 20 - 26 See details
65
Global rank
79 infographic chevron month
Month rank
71 infographic chevron week
Week rank
158
IOCs

FlawedAmmmyy is a RAT type malware that can be used to perform actions remotely on an infected PC. This malware is well known for being featured in especially large campaigns with wide target demographics.

Trojan
Type
Unknown
Origin
1 January, 2016
First seen
31 October, 2020
Last seen

How to analyze FlawedAmmyy with ANY.RUN

Type
Unknown
Origin
1 January, 2016
First seen
31 October, 2020
Last seen

IOCs

IP addresses
185.99.132.119
169.239.129.27
185.99.132.12
169.239.129.113
185.99.133.83
169.239.128.15
185.99.133.140
169.239.128.186
169.239.129.45
136.243.104.242
136.243.104.235
Hashes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 Seen at

Recent blog posts

post image
ANY.RUN attends Osintomático 2024
watchers 54
comments 0
post image
Windows 11 UAC Bypass in Modern Malware
watchers 768
comments 0
post image
New Hijack Loader Variant: Uses Process Hollo...
watchers 573
comments 0

What is FlawedAmmyy malware?

FlawedAmmyy is a Remote Access Trojan – a malware that is utilized by attackers to take full control over the target machine. It is based on the source code of a completely legitimate program Ammyy Admin. Despite this RAT being recorded as a new malware in 2018, some researchers suggest that it has been in use since 2016.

FlawedAmmyy has been used by multiple attackers in massive email-spam campaigns as well as in highly targeted cyber attacks aimed at businesses in the automotive industry. Among others, a well-known hacker operating under the alias TA505 is known to have been using this malware in large-scale campaigns.

General description of FlawedAmmyy malware

Being built using leaked source code of the third version of Ammyy Admin – which is legitimate remote access and administration program – Flawed Ammyy enables attackers to perform multiple actions on infected Windows PCs. With this malware, hackers can control the desktop remotely, manipulate files, steal credentials, and access audio on an infected machine to potentially collect information about their victims.

The popularity of FlawedAmmy started rising especially quickly in 2018, as the focus of malicious actors started shifting from operating ransomware to other types of malicious programs. In particular, in November of 2018, a threat actor known as TA505 started distributing various loader viruses in their spam email campaigns – using ServHelper at first and later switching to AndroMut – with the end goal of infecting victims with FlawedAmmyy.

In particular, researchers have detected two separate campaigns that distributed FlawedAmmyy using AndroMut loader – the first campaign targeted victims in South Korea with HTML attachments designed to download an Office file with malicious macros which installed a loader which would, in turn, drop the main payload – FlawedAmmyy RAT. The scope of other campaigns featuring AndroMut was more broad and included enterprises in the USA, UAE, and Singapore.

Other campaigns not necessarily by TA505 that took place in 2019 made use of an XLM document that contained a malicious macro that downloaded FlawedAmmyy directly, bypassing the loader stage.

FlawedAmmyy malware analysis

A video recorded in the ANY.RUN malware hunting service displays the execution process of FlawedAmmyy, allowing one to examine it in a convenient and safe environment.

flawedammyy execution process graph

Figure 1: Displays the graph of processes generated by the ANY.RUN malware analyzing service

text report of the flawedammyy analysis

Figure 2: Even more information about the execution of malware can be found in customizable text reports generated by ANY.RUN

FlawedAmmyy execution process

Usually, Flawed Ammyy makes its way into the machine through mail spam in a form of a MS Word or MS Excel document with a malicious macro. Examples of such malicious docs you can find on ANY.RUN's public submissions browsing by tag maldoc-21. After the malicious .xls file is opened, it automatically runs a macro function that runs either msiexec.exe or cmd.exe to download and execute the first stage payload. This first stage executable file then downloads and decrypts another file, which usually has a filename "wsus.exe" and it is the FlawedAmmyy malware itself. Wsus.exe creates persistence in the system and communicates with C2 servers.

Sometimes malicious executable files are digitally signed with a certificate from trusted vendors. Also, it's interesting that trojan checks the user privileges and presence of Anti-Virus programs on the infected machine and changes behavior based on the results of this check. You can also find out how this execution method differs from Trickbot and Zloader.

Distribution of FlawedAmmyy RAT

FlawedAmmyy is distributed with spam email campaigns with subjects usually concerning invoices or receipts. Emails can contain a .zip attachment disguised to contain information related to the email subject, a Microsoft Office file, or an XML attachment. Attached files, in reality, can hold a URL that automatically opens a browser window and redirects victims to a website from where malware samples would be downloaded.

In some campaigns, another virus designed to install the final payload is downloaded first and it then drops FlawedAmmyy onto the machine. Other campaigns made use of something called the Server Message Block (SMB) protocol to download malware directly, bypassing the browser download which is quite a rare trick for malware.

How to prevent FlawedAmmyy attacks?

Once FlawedAmmyy infects a PC, it can operate discreetly without letting users know that their machine is in fact infected. This allows attackers to collect various information about their victims over time and makes this malware potentially very destructive.

However, adhering to simple online safety tips can make avoiding the infection fairly easy – as long as a user never clicks on suspicious links or downloads emails from unknown senders they will be safe. However, things get a little bit more complicated with FlawedAmmy since some of the attacks are very targeted and feature believable emails.

Therefore users are advised to conduct their own checks about email authenticity and pay attention to small details before downloading files or following URLs in their correspondence.

How to export FlawedAmmyy data using ANY.RUN?

Analysts can export all significant events from a task to MISP for further analysis and export to IDS/SIEM systems or simply for share. Just click on the "Export" button and choose "MIST JSON format" in the drop-down menu.

export events from the task with flawedammyy into MISP JSON Figure 3: Export events from the task with flawedammyy into MISP JSON

Summary

FlawedAmmyy RAT is an interesting malware that is capable of operating stealthily on infected machines and causing potentially serious damage with its remote access capabilities. It was featured both in massive, large-scale email spam campaigns as well as in targeted attacks against businesses operating in particular industries which indicates the diversity that operators behind this malware can show in regard to choosing their victims.

Security researchers only documented this malware in 2018 despite its being around since 2016, which means that it managed to operate in the dark for two whole years, evading researchers or maybe even tricking them. Thankfully, modern malware analysis services like ANY.RUN provides multiple specially designed tools to simplify and greatly streamline the research process to help us identify current and future threats.

HAVE A LOOK AT

Adwind screenshot
Adwind
adwind trojan
Adwind RAT, sometimes also called Unrecom, Sockrat, Frutas, jRat, and JSocket, is a Malware As A Service Remote Access Trojan that attackers can use to collect information from infected machines. It was one of the most popular RATs in the market in 2015.
Read More
Agent Tesla screenshot
Agent Tesla
agenttesla trojan rat stealer
Agent Tesla is spyware that collects information about the actions of its victims by recording keystrokes and user interactions. It is falsely marketed as a legitimate software on the dedicated website where this malware is sold.
Read More
Amadey screenshot
Amadey
amadey
Amadey is a formidable Windows infostealer threat, characterized by its persistence mechanisms, modular design, and ability to execute various malicious tasks.
Read More
Arkei screenshot
Arkei
arkei stealer
Arkei is a stealer type malware capable of collecting passwords, autosaved forms, cryptocurrency wallet credentials, and files.
Read More
AsyncRAT screenshot
AsyncRAT
asyncrat
AsyncRAT is a RAT that can monitor and remotely control infected systems. This malware was introduced on Github as a legitimate open-source remote administration software, but hackers use it for its many powerful malicious functions.
Read More
WarZone screenshot
WarZone
warzone avemaria stealer trojan rat
WarZone RAT is a remote access trojan, which is written in C++ and offered as a malware-as-a-service. It packs a wide range of capabilities, from stealing victims’ files and passwords to capturing desktop activities. WarZone RAT is primarily distributed via phishing emails and receives regular updates from its C2.
Read More

Our website uses cookies. By visiting the pages of the site, you agree to our Privacy Policy