The Android banking trojan known as Vultur has resurfaced with a suite of new features and improved anti-analysis and detection evasion techniques, enabling its operators to remotely interact with a mobile device and harvest sensitive data.

“Vultur has also started masquerading more of its malicious activity by encrypting its C2 communication, using multiple encrypted payloads that are decrypted on the fly, and using the guise of legitimate applications to carry out its malicious actions,” NCC Group researcher Joshua Kamp said in a report published last week.

Vultur was first disclosed in early 2021, with the malware capable of leveraging Android’s accessibility services APIs to execute its malicious actions.

The malware has been observed to be distributed via trojanized dropper apps on the Google Play Store, masquerading as authenticator and productivity apps to trick unwitting users into installing them. These dropper apps are offered as part of a dropper-as-a-service (DaaS) operation called Brunhilda.

Other attack chains, as observed by NCC Group, involve the droppers being spread using a combination of SMS messages and phone calls – a technique called telephone-oriented attack delivery (TOAD) – to ultimately serve an updated version of the malware.

“The first SMS message guides the victim to a phone call,” Kamp said. When the victim calls the number, the fraudster provides the victim with a second SMS that includes the link to the dropper: a modified version of the [legitimate] McAfee Security app.”

The initial SMS message aims to induce a false sense of urgency by instructing the recipients to call a number to authorize a non-existent transaction that involves a large sum of money.

Upon installation, the malicious dropper executes three related payloads (two APKs and one DEX file) that register the bot with the C2 server, obtain accessibility services permissions for remote access via AlphaVNC and ngrok, and run commands fetched from the C2 server.

One of the prominent additions to Vultur is the ability to remotely interact with the infected device, including carrying out clicks, scrolls, and swipes, through Android’s accessibility services, as well as download, upload, delete, install, and find files.

In addition, the malware is equipped to prevent the victims from interacting with a predefined list of apps, display custom notifications in the status bar, and even disable Keyguard to bypass lock screen security measures.

“Vultur’s recent developments have shown a shift in focus towards maximizing remote control over infected devices,” Kamp said.

“With the capability to issue commands for scrolling, swipe gestures, clicks, volume control, blocking apps from running, and even incorporating file manager functionality, it is clear that the primary objective is to gain total control over compromised devices.”

The development comes as Team Cymru revealed the Octo (aka Coper) Android banking trojan’s transition to a malware-as-a-service operation, offering its services to other threat actors for conducting information theft.

“The malware offers a variety of advanced features, including keylogging, interception of SMS messages and push notifications, and control over the device’s screen,” the company said.

“It employs various injects to steal sensitive information, such as passwords and login credentials, by displaying fake screens or overlays. Additionally, it utilizes VNC (Virtual Network Computing) for remote access to devices, enhancing its surveillance capabilities.”

Octo campaigns are estimated to have compromised 45,000 devices, primarily spanning Portugal, Spain, Turkey, and the U.S. Some of the other victims are located in France, the Netherlands, Canada, India, and Japan.

The findings also follow the emergence of a new campaign targeting Android users in India that distributes malicious APK packages posing as online booking, billing, and courier services via a malware-as-a-service (MaaS) offering.

The malware “targets theft of banking information, SMS messages, and other confidential information from victims’ devices,” Broadcom-owned Symantec said in a bulletin.

Mar 22, 2024NewsroomLinux / Cyber Warfare

The data wiping malware called AcidPour may have been deployed in attacks targeting four telecom providers in Ukraine, new findings from SentinelOne show.

The cybersecurity firm also confirmed connections between the malware and AcidRain, tying it to threat activity clusters associated with Russian military intelligence.

“AcidPour’s expanded capabilities would enable it to better disable embedded devices including networking, IoT, large storage (RAIDs), and possibly ICS devices running Linux x86 distributions,” security researchers Juan Andres Guerrero-Saade and Tom Hegel said.

AcidPour is a variant of AcidRain, a wiper that was used to render Viasat KA-SAT modems operable at the onset of the Russo-Ukrainian war in early 2022 and cripple Ukraine’s military communications.

It also builds upon the latter’s features, while targeting Linux systems running on x86 architecture. AcidRain, on the other hand, is compiled for MIPS architecture.

Where AcidRain was more generic, AcidPour incorporates logic to target embedded devices, Storage Area Networks (SANs), Network Attached Storage (NAS) appliances, and dedicated RAID arrays.

That said, both the strains overlap when it comes to the use of the reboot calls and the method employed for recursive directory wiping. Also identical is the IOCTLs-based device-wiping mechanism that also shares commonalities with another malware linked to Sandworm known as VPNFilter.

“One of the most interesting aspects of AcidPour is its coding style, reminiscent of the pragmatic CaddyWiper broadly utilized against Ukrainian targets alongside notable malware like Industroyer 2,” the researchers said.

The C-based malware comes with a self-delete function that overwrites itself on disk at the beginning of its execution, while also employing an alternate wiping approach depending on the device type.

AcidPour has been attributed to a hacking crew tracked as UAC-0165, which is associated with Sandworm and has a track record of striking Ukrainian critical infrastructure.

The Computer Emergency Response Team of Ukraine (CERT-UA), in October 2023, implicated the adversary to attacks targeting at least 11 telecommunication service providers in the country between May and September of last year.

“[AcidPour] could have been used in 2023,” Hegel told The Hacker News. “It’s likely the actor has made use of AcidRain/AcidPour related tooling consistently throughout the war. A gap in this perspective speaks to the level of insight the public often has to cyber intrusions – generally quite limited and incomplete.”

The ties to Sandworm are further bolstered by the fact that a threat actor known as Solntsepyok (aka Solntsepek or SolntsepekZ) claimed to have infiltrated four different telecommunication operators in Ukraine and disrupted their services on March 13, 2024, three days prior to the discovery of AcidPour.

Solntsepyok, according to the State Special Communications Service of Ukraine (SSSCIP), is a Russian advanced persistent threat (APT) with likely ties to the Main Directorate of the General Staff of the Armed Forces of the Russian Federation (GRU), which also operates Sandworm.

It’s worth pointing out that Solntsepyok has also been accused of hacking into Kyivstar’s systems as early as May 2023. The breach came to light in late December.

While it’s currently not clear if AcidPour was used in the latest set of attacks, the discovery suggests that threat actors are constantly refining their tactics to stage destructive assaults and inflict significant operational impact.

“This progression reveals not only a refinement in the technical capabilities of these threat actors but also their calculated approach to select targets that maximize follow-on effects, disrupting critical infrastructure and communications,” the researchers said.