The dirty dozen of Latin America: From Amavaldo to Zumanek

Besides Amavaldo, which became dormant, all the other families remain active to this day.
Brazil is still the most targeted country, followed by Spain and Mexico.
Grandoreiro and Mekotio expanded to Europe – mainly Spain.
What started as several minor campaigns, likely to test the new territory, evolved into something much grander.
Latin American banking trojans used to change rapidly.
In the early days of tracking, some of them were adding to or modifying their core features several times a month.
Nowadays they still change very often, but the core seems to remain mostly untouched.
Due to the partially stabilized development, researchers believe the operators are now focusing on improving distribution.

The campaigns researchers see always come in waves and more than 90% of them are distributed through spam.
One campaign usually lasts for a week at most. Previously, researchers have seen Grandoreiro, Ousaban and Casbaneiro increasing their reach enormously compared to their previous activity,
Latin American banking trojans require a lot of conditions to attack successfully:

– Potential victims need to follow steps required to install the malware on their machines
– Victims need to visit a targeted website and log into their accounts
– Operators need to react to this situation and manually command the malware to display the fake pop-up window and take control of the victim’s machine
– Victims need to not suspect malicious activity and possibly even enter an authentication code in the case of 2FA

This malware family was active in Brazil.
Its most noticeable characteristic was its usage of well-known cryptographic methods to encrypt strings, as opposed to the majority of Latin American banking trojans that mainly use custom encryption schemes, some of which are shared across these families.
Researchers have observed Krachulka variants using AES, RC2, RC4, 3DES and a slightly customized variant of Salsa20.

Krachulka, despite being written in Delphi like most other Latin American banking trojans, was distributed by a downloader written in the Go programming language – another unique characteristic among this kind of banking malware.

Researchers were able to identify additional builds, each dedicated to target a different country – Brazil, Chile and Colombia.
The most identifying feature of Lokorrito is its usage of a custom User-Agent string in network communication.
Researchers have observed two values – LA CONCHA DE TU MADRE and 4RR0B4R 4 X0T4 D4 TU4 M4E, both quite vulgar expressions in Spanish and Portuguese, respectively.
Researchers have identified several additional Lokorrito-related modules.
First, a backdoor, which basically functions like a simplified version of the banking trojan without the support for fake overlay windows.
Researchers believe it was installed in some Lokorrito campaigns first and, only if the attacker saw fit, it was updated to the actual banking trojan.
Then, a spam tool, which generates spam emails distributing Lokorrito and sending them to further potential victims.
The tool generated the emails based on both hardcoded data and data obtained from a C&C server.
Finally, researchers identified a simple infostealer designed to steal the victim’s Outlook address book and a password stealer intended to harvest Outlook and FileZilla credentials.

This malware family was active exclusively in Brazil.
It was the first Latin American banking trojan malware family ESET identified.

Zumanek is identified by its method for obfuscating strings.
It creates a function for each character of the alphabet and then concatenates the result of calling the correct functions in sequence.

Sign Up For Threat Alerts

Threats Icon

Dec 08, 2022

Trigona (._locked) ransomware virus

Trigona is ransomware that encrypts files and appends the "._locked" extension to filenames. Also, it...

Threats Icon

Dec 08, 2022

Threat Actors Target Exposed Remote Desktop Protocol...

Threat actors were discovered targeting open Remote Desktop Protocol (RDP) ports with variants from a...

Threats Icon

Dec 07, 2022

Redigo Backdoor Malware Targets Redis Servers

The Redigo backdoor is written in the Go programming language and targets Redis servers vulnerable...

Threats Icon

Dec 06, 2022

DuckLogs MaaS (Malware-as-a-Service) Provides Sophisticated Features

DuckLogs is MaaS (Malware-as-a-Service) advertised on cybercrime forums with a range of features including remote...

Threats Icon

Dec 05, 2022

WannaRen Returns As Life Ransomware

WannaRen ransomware appeared on the threat landscape in 2020 and reemerged in 2022 as Life...

Threats Icon

Dec 04, 2022

Alert (AA22-335A) Cuba Ransomware

The Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) are...

Threats Icon

Dec 01, 2022

UNC4191 Threat Group Targets Entities In The...

The UNC4191 threat group was discovered targeting entities in the Philippines with custom malware and...

Threats Icon

Nov 30, 2022

Emotet Leads To Quantum Ransomware Infection

Threat actors were observed using Emotet to gain access to the victim's network and deploy...

Threats Icon

Nov 29, 2022

RansomExx Upgrades to Rust

IBM Security X-Force Threat Researchers have discovered a new variant of the RansomExx ransomware that...

Threats Icon

Nov 29, 2022

Ransomware Roundup: Cryptonite Ransomware

FortiGuard Labs has reported on Cryptonite ransomware, which was found to target Microsoft Windows machines...

Threats Icon

Nov 28, 2022

Operation Typhoon: The Cyber Sea Lotus Coveting...

Cyber espionage actors, now designated by FireEye as APT32 (OceanLotus Group), are carrying out intrusions...

Threats Icon

Nov 27, 2022

IL-Cert Alert – Active phishing campaign in...

There is a new phishing campaign in Israel. The malware relies upon user execution. The...

Threats Icon

Nov 27, 2022

Emotets Vacation Is Over: No Rest For...

Emotet started as a banking Trojan in spreading via spam campaigns by imitating financial statements,...

Threats Icon

Nov 24, 2022

Aurora: A Rising Stealer Flying Under The...

Aurora is a multipurpose botnet with data collection, information stealer, downloading, and remote access Trojan...

Threats Icon

Nov 23, 2022

Analysis Of The ViperSoftX And VenomSoftX Information...

Torrents and software-sharing sites are being used to target victims across the globe with variants...