During our threat hunting exercises in recent months, we’ve started to observe a distinguishing pattern of msiexec.exe usage across different endpoints. As we drilled down to individual assets, we found traces of a recently discovered malware called Raspberry Robin. The RedCanary Research Team first coined the name for this malware in their blog post, and Sekoia published a Flash Report about the activity under the name of QNAP Worm. Both articles offer great analysis of the malware’s behavior. Our findings support and enrich prior research on the topic.
Raspberry Robin is a worm that spreads over an external drive. After initial infection, it downloads its payload through msiexec.exe from QNAP cloud accounts, executes its code through rundll32.exe, and establishes a command and control (C2) channel through TOR connections.
Let’s walkthrough the steps of the kill-chain to see how this malware functions.
Raspberry Robin is delivered through infected external disks. Once attached, cmd.exe tries to execute commands from a file within that disk. This file is either a .lnk file or a file with a specific naming pattern. Files with this pattern exhibit a 2 to 5 character name with an usually obscure extension, including .swy, .chk, .ico, .usb, .xml, and .cfg. Also, the attacker uses an excessive amount of whitespace/non printable characters and changing letter case to avoid string matching detection techniques. Example command lines include:
File sample for delivery can be found in this URL:
https://www.virustotal.com/gui/file/04c13e8b168b6f313745be4034db92bf725d47091a6985de9682b21588b8bcae/relations
Next, we observe explorer.exe running with an obscure command line argument, spawned by a previous instance of cmd.exe. This obscure argument seems to take the name of an infected external drive or .lnk file that was previously executed. Some of the samples had values including USB, USB DISK, or USB Drive, while some other samples had more specific names. On every instance of explorer.exe we see that the adversary is changing the letter case to avoid detection:
After delivery and initial execution, cmd.exe spawns msiexec.exe to download the Raspberry Robin payload. It uses -q or /q together with standard installation parameter to operate quietly. Once again, mixed case letters are used to bypass detection:
As you can see above, URLs used for payload download have a specific pattern. Domains use 2 to 4 character names with obscure TLDs including .xyz, .hk, .info, .pw, .cx, .me, and more. URL paths have a single directory with a random string 11 characters long, followed by hostname and the username of the victim. On network telemetry, we also observed the Windows Installer user agent due to the usage of msiexec.exe. To detect Raspberry Robin through its URL pattern, use this regex:
^http[s]{0,1}\:\/\/[a-zA-Z0-9]{2,4}\.[a-zA-Z0-9]{2,6}\:8080\/[a-zA-Z0-9]+\/.*?(?:-|\=|\?).*?$
If we look up the WHOIS information for given domains, we see domain registration dates going as far back as February 2015. We also see an increase on registered domains starting from September 2021, which aligns with initial observations of Raspberry Robin by our peers.
WHOIS Creation Date | Count |
12/9/2015 | 1 |
… | … |
10/8/2020 | 1 |
11/14/2020 | 1 |
7/3/2021 | 1 |
7/26/2021 | 2 |
9/11/2021 | 2 |
9/23/2021 | 9 |
9/24/2021 | 6 |
9/26/2021 | 4 |
9/27/2021 | 2 |
11/9/2021 | 3 |
11/10/2021 | 1 |
11/18/2021 | 2 |
11/21/2021 | 3 |
12/11/2021 | 7 |
12/31/2021 | 7 |
1/17/2022 | 6 |
1/30/2022 | 11 |
1/31/2022 | 3 |
4/17/2022 | 5 |
Table 1: Distribution of domain creation dates over time
Associated domains have SSL certificates with the subject alternative name of q74243532.myqnapcloud.com, which points out the underlying QNAP cloud infra. Also, their URL scan results return login pages to QTS service of QNAP:
Once the payload is downloaded, it is executed through various system binaries. First, rundll32.exe uses the ShellExec_RunDLL function from shell32.dll to leverage system binaries such as msiexec.exe, odbcconf.exe, or control.exe. These binaries are used to execute the payload stored in C:\ProgramData\[3 chars]\
It is followed by the execution of fodhelper.exe, which has the auto elevated bit set to true. It is often leveraged by adversaries in order to bypass User Account Control and execute additional commands with escalated privileges [3]. To monitor suspicious executions of fodhelper.exe, we suggest monitoring its instances without any command line arguments.
Raspberry Robin sets up its C2 channel through the additional execution of system binaries without any command line argument, which is quite unusual. That likely points to process injection given elevated privileges in previous steps of execution. It uses dllhost.exe, rundll32.exe, and regsvr32.exe to set up a TOR connection.
In Cisco Global Threat Alerts available through Cisco Secure Network Analytics and Cisco Secure Endpoint, we track this activity under the Raspberry Robin threat object. Image 3 shows a detection sample of Raspberry Robin:
Raspberry Robin tries to remain undetected through its use of system binaries, mixed letter case, TOR-based C2, and abuse of compromised QNAP accounts. Although we have similar intelligence gaps (how it infects external disks, what are its actions on objective) like our peers, we are continuously observing its activities.
Type | Stage | IOC |
Domain | Payload Delivery | k6j[.]pw |
Domain | Payload Delivery | kjaj[.]top |
Domain | Payload Delivery | v0[.]cx |
Domain | Payload Delivery | zk4[.]me |
Domain | Payload Delivery | zk5[.]co |
Domain | Payload Delivery | 0dz[.]me |
Domain | Payload Delivery | 0e[.]si |
Domain | Payload Delivery | 5qw[.]pw |
Domain | Payload Delivery | 6w[.]re |
Domain | Payload Delivery | 6xj[.]xyz |
Domain | Payload Delivery | aij[.]hk |
Domain | Payload Delivery | b9[.]pm |
Domain | Payload Delivery | glnj[.]nl |
Domain | Payload Delivery | j4r[.]xyz |
Domain | Payload Delivery | j68[.]info |
Domain | Payload Delivery | j8[.]si |
Domain | Payload Delivery | jjl[.]one |
Domain | Payload Delivery | jzm[.]pw |
Domain | Payload Delivery | k6c[.]org |
Domain | Payload Delivery | kj1[.]xyz |
Domain | Payload Delivery | kr4[.]xyz |
Domain | Payload Delivery | l9b[.]org |
Domain | Payload Delivery | lwip[.]re |
Domain | Payload Delivery | mzjc[.]is |
Domain | Payload Delivery | nt3[.]xyz |
Domain | Payload Delivery | qmpo[.]art |
Domain | Payload Delivery | tiua[.]uk |
Domain | Payload Delivery | vn6[.]co |
Domain | Payload Delivery | z7s[.]org |
Domain | Payload Delivery | k5x[.]xyz |
Domain | Payload Delivery | 6Y[.]rE |
Domain | Payload Delivery | doem[.]Re |
Domain | Payload Delivery | bpyo[.]IN |
Domain | Payload Delivery | l5k[.]xYZ |
Domain | Payload Delivery | uQW[.]fUTbOL |
Domain | Payload Delivery | t7[.]Nz |
Domain | Payload Delivery | 0t[.]yT |
xmas-1200-35-wide
hny-1200
WormGPT, a private new chatbot service advertised as a way to use Artificial Intelligence (AI) to write malicious software without all the pesky prohibitions on such activity enforced by the likes of ChatGPT and Google Bard, has started adding restrictions of its own on how the service can be used. Faced with customers trying to use WormGPT to create ransomware and phishing scams, the 23-year-old Portuguese programmer who created the project now says his service is slowly morphing into “a more controlled environment.”
Image: SlashNext.com.
The large language models (LLMs) made by ChatGPT parent OpenAI or Google or Microsoft all have various safety measures designed to prevent people from abusing them for nefarious purposes — such as creating malware or hate speech. In contrast, WormGPT has promoted itself as a new, uncensored LLM that was created specifically for cybercrime activities.
WormGPT was initially sold exclusively on HackForums, a sprawling, English-language community that has long featured a bustling marketplace for cybercrime tools and services. WormGPT licenses are sold for prices ranging from 500 to 5,000 Euro.
“Introducing my newest creation, ‘WormGPT,’ wrote “Last,” the handle chosen by the HackForums user who is selling the service. “This project aims to provide an alternative to ChatGPT, one that lets you do all sorts of illegal stuff and easily sell it online in the future. Everything blackhat related that you can think of can be done with WormGPT, allowing anyone access to malicious activity without ever leaving the comfort of their home.”
In July, an AI-based security firm called SlashNext analyzed WormGPT and asked it to create a “business email compromise” (BEC) phishing lure that could be used to trick employees into paying a fake invoice.
“The results were unsettling,” SlashNext’s Daniel Kelley wrote. “WormGPT produced an email that was not only remarkably persuasive but also strategically cunning, showcasing its potential for sophisticated phishing and BEC attacks.”
A review of Last’s posts on HackForums over the years shows this individual has extensive experience creating and using malicious software. In August 2022, Last posted a sales thread for “Arctic Stealer,” a data stealing trojan and keystroke logger that he sold there for many months.
“I’m very experienced with malwares,” Last wrote in a message to another HackForums user last year.
Last has also sold a modified version of the information stealer DCRat, as well as an obfuscation service marketed to malicious coders who sell their creations and wish to insulate them from being modified or copied by customers.
Shortly after joining the forum in early 2021, Last told several different Hackforums users his name was Rafael and that he was from Portugal. HackForums has a feature that allows anyone willing to take the time to dig through a user’s postings to learn when and if that user was previously tied to another account.
That account tracing feature reveals that while Last has used many pseudonyms over the years, he originally used the nickname “ruiunashackers.” The first search result in Google for that unique nickname brings up a TikTok account with the same moniker, and that TikTok account says it is associated with an Instagram account for a Rafael Morais from Porto, a coastal city in northwest Portugal.
Reached via Instagram and Telegram, Morais said he was happy to chat about WormGPT.
“You can ask me anything,” Morais said. “I’m an open book.”
Morais said he recently graduated from a polytechnic institute in Portugal, where he earned a degree in information technology. He said only about 30 to 35 percent of the work on WormGPT was his, and that other coders are contributing to the project. So far, he says, roughly 200 customers have paid to use the service.
“I don’t do this for money,” Morais explained. “It was basically a project I thought [was] interesting at the beginning and now I’m maintaining it just to help [the] community. We have updated a lot since the release, our model is now 5 or 6 times better in terms of learning and answer accuracy.”
WormGPT isn’t the only rogue ChatGPT clone advertised as friendly to malware writers and cybercriminals. According to SlashNext, one unsettling trend on the cybercrime forums is evident in discussion threads offering “jailbreaks” for interfaces like ChatGPT.
“These ‘jailbreaks’ are specialised prompts that are becoming increasingly common,” Kelley wrote. “They refer to carefully crafted inputs designed to manipulate interfaces like ChatGPT into generating output that might involve disclosing sensitive information, producing inappropriate content, or even executing harmful code. The proliferation of such practices underscores the rising challenges in maintaining AI security in the face of determined cybercriminals.”
Morais said they have been using the GPT-J 6B model since the service was launched, although he declined to discuss the source of the LLMs that power WormGPT. But he said the data set that informs WormGPT is enormous.
“Anyone that tests wormgpt can see that it has no difference from any other uncensored AI or even chatgpt with jailbreaks,” Morais explained. “The game changer is that our dataset [library] is big.”
Morais said he began working on computers at age 13, and soon started exploring security vulnerabilities and the possibility of making a living by finding and reporting them to software vendors.
“My story began in 2013 with some greyhat activies, never anything blackhat tho, mostly bugbounty,” he said. “In 2015, my love for coding started, learning c# and more .net programming languages. In 2017 I’ve started using many hacking forums because I have had some problems home (in terms of money) so I had to help my parents with money… started selling a few products (not blackhat yet) and in 2019 I started turning blackhat. Until a few months ago I was still selling blackhat products but now with wormgpt I see a bright future and have decided to start my transition into whitehat again.”
WormGPT sells licenses via a dedicated channel on Telegram, and the channel recently lamented that media coverage of WormGPT so far has painted the service in an unfairly negative light.
“We are uncensored, not blackhat!” the WormGPT channel announced at the end of July. “From the beginning, the media has portrayed us as a malicious LLM (Language Model), when all we did was use the name ‘blackhatgpt’ for our Telegram channel as a meme. We encourage researchers to test our tool and provide feedback to determine if it is as bad as the media is portraying it to the world.”
It turns out, when you advertise an online service for doing bad things, people tend to show up with the intention of doing bad things with it. WormGPT’s front man Last seems to have acknowledged this at the service’s initial launch, which included the disclaimer, “We are not responsible if you use this tool for doing bad stuff.”
But lately, Morais said, WormGPT has been forced to add certain guardrails of its own.
“We have prohibited some subjects on WormGPT itself,” Morais said. “Anything related to murders, drug traffic, kidnapping, child porn, ransomwares, financial crime. We are working on blocking BEC too, at the moment it is still possible but most of the times it will be incomplete because we already added some limitations. Our plan is to have WormGPT marked as an uncensored AI, not blackhat. In the last weeks we have been blocking some subjects from being discussed on WormGPT.”
Still, Last has continued to state on HackForums — and more recently on the far more serious cybercrime forum Exploit — that WormGPT will quite happily create malware capable of infecting a computer and going “fully undetectable” (FUD) by virtually all of the major antivirus makers (AVs).
“You can easily buy WormGPT and ask it for a Rust malware script and it will 99% sure be FUD against most AVs,” Last told a forum denizen in late July.
Asked to list some of the legitimate or what he called “white hat” uses for WormGPT, Morais said his service offers reliable code, unlimited characters, and accurate, quick answers.
“We used WormGPT to fix some issues on our website related to possible sql problems and exploits,” he explained. “You can use WormGPT to create firewalls, manage iptables, analyze network, code blockers, math, anything.”
Morais said he wants WormGPT to become a positive influence on the security community, not a destructive one, and that he’s actively trying to steer the project in that direction. The original HackForums thread pimping WormGPT as a malware writer’s best friend has since been deleted, and the service is now advertised as “WormGPT – Best GPT Alternative Without Limits — Privacy Focused.”
“We have a few researchers using our wormgpt for whitehat stuff, that’s our main focus now, turning wormgpt into a good thing to [the] community,” he said.
It’s unclear yet whether Last’s customers share that view.