ZeroHour

Search: “sampling”

8 stories

Redtail Payload Analysis [Guest Diary], (Wed, Sep 9th)

SANS guest analyst detonated a RedTail Linux sample from a DShield honeypot, finding process masquerading as php-fpm, monitoring-kill behavior, and a TCP listener.

A DShield honeypot captured multi-architecture RedTail Linux executables (ARM, ARM64, i686, RISC-V, x86-64) deployed via shell scripts. Dynamic analysis of the UPX-packed, statically linked x86-64 sample (SHA-256 63be5f38...d35e) in an isolated Ubuntu 24.04 VM on Proxmox showed it renamed its process via prctl(PR_SET_NAME), killed a filesystem-monitoring process, and opened a TCP listening socket while surviving processes posed as php-fpm or PostgreSQL-like workers. Differential memory images pre- and post-execution were captured from the hypervisor for forensics.

SANS Internet Storm Center · 6d agoMalware in the wild1

CryptoBit: Another Ransomware Family Gets an Update

Palo Alto Unit 42 analyzes updated CryptoBit ransomware distributed via the Rig exploit kit, documenting IOCs, eight sample hashes, and disguise tactics from June 2016.

Unit 42 observed an updated CryptoBit ransomware variant (also tracked as CriptoBit or Mobef) delivered through the Rig exploit kit via the gate domain realstatistics.info between June 17-27, 2016. Infections targeted Windows hosts with out-of-date Flash plugins, and post-infection callbacks used fake user-agents and referrers to disguise traffic to laoismacau.com. At least eight samples were collected, and by June 27 the campaign had begun distributing other malware.

Palo Alto Unit 42 · Aug 17, 2026Ransomware in the wild

Malspam Targeting Brazil Continues to Evolve

Brazilian malspam campaigns continue evolving, abusing Google URL shortener and Dropbox and using Squiblydoo plus DLL side-loading to deploy likely infostealing botnet malware.

A June 2017 Brazilian malspam campaign spoofed IPTU tax notification emails, using the recipient's address as the sender, and abused Google's URL shortener and Dropbox to deliver a zip containing a malicious Windows shortcut (.lnk) file. The LNK used the Squiblydoo technique (regsvr32.exe) to download and execute a scriptlet with elevated privileges, retrieving a signed G-Buster Browser Defense executable alongside a malicious fltLib.dll loaded via side-loading, likely an information-stealing botnet. Post-infection HTTP traffic exposed over 400 infected Windows hosts, mostly in Brazil, with 2,132 Banload-tagged samples observed in the first half of 2017.

Palo Alto Unit 42 · Aug 17, 2026Malware in the wild

Muhstik Botnet Attacks Tomato Routers to Harvest New IoT Devices

Unit 42 found a Muhstik botnet variant brute-forcing Tomato router web authentication to harvest IoT devices for crypto mining and DDoS attacks.

Palo Alto Networks Unit 42 researchers in December 2019 identified a new Muhstik botnet variant scanning Tomato routers on TCP 8080 and brute-forcing default admin credentials, targeting roughly 4,600 exposed devices found via Shodan. The variant also scans WordPress and Webuzo installations and exploits the Oracle WebLogic deserialization flaw CVE-2019-2725 for unauthenticated remote code execution. Muhstik, active since March 2018, self-propagates like a worm and typically monetizes infections through cryptocurrency mining and DDoS attacks controlled via an IRC C2 channel.

Palo Alto Unit 42 · 28d agoMalware in the wildCVE-2019-2725

Eleethub: A Cryptocurrency Mining Botnet with Rootkit for Self

Unit 42 uncovered Eleethub, a Perl-based Bitcoin mining botnet using a crafted rootkit and libprocesshider to evade detection, still under development with few infections.

Unit 42 discovered an under-development Perl Shellbot campaign that mines Bitcoin using xmrig and emech while evading detection via a rootkit that replaces the ps tool and the LD_PRELOAD-based libprocesshider.so library. Infected devices download a malicious shell script, connect to IRC-based C2 at eleethub.com and the UnderNet network, and can receive commands for UDP/TCP floods, port scans, and HTTP attacks. The botnet can affect Unix systems and Windows 10 hosts running a Linux subsystem, and its operators use the 'Los Zetas' branding, though they are unlikely to be the Mexican drug cartel. Researchers found only a few compromised 'zombies' before the campaign expanded.

Palo Alto Unit 42 · 28d agoMalware in the wild

Mole Ransomware: How One Malicious Spam Campaign Quickly Increased Complexity and Changed Tactics

Unit 42 tracks the new Mole ransomware (CryptoMix family) spread via USPS-themed malspam, with tactics escalating to JavaScript downloaders dropping multiple malware families.

On April 11, 2017, a malspam campaign began distributing Mole ransomware, a CryptoMix-family strain, through USPS-themed emails linking to fake Microsoft Word Online sites offering a bogus Office plugin. By April 13 the campaign added Nemucod JavaScript downloaders installing Mole alongside Kovter and Miuref, and by April 18 it switched to the KINS banking Trojan before moving to speeding-ticket themes and a fake parking services website. Unit 42 notes the rapid tactic changes are likely intended to evade detection, and CryptoMix variants like Mole are typically repackaged within weeks.

Palo Alto Unit 42 · Aug 17, 2026Ransomware in the wild

Locky Ransomware Installed Through Nuclear EK

Unit 42 reports Locky ransomware delivered through the Nuclear exploit kit using Flash exploits, adding a drive-by path to existing malspam distribution.

Unit 42 observed Locky ransomware being delivered by the Nuclear exploit kit in March 2016 via Flash exploits, following February reports of Neutrino EK distributing Locky. Infections follow a drive-by chain through a gate to the Nuclear EK, which either installs Locky directly or drops a downloader that retrieves it from another domain. Locky retains two distribution paths: malspam with malicious Office macros or JavaScript attachments and exploit kit traffic triggered by casual web browsing.

Palo Alto Unit 42 · Aug 17, 2026Ransomware in the wild1

Afraidgate: Major Exploit Kit Campaign Switches from CryptXXX Ransomware Back to Locky

The Afraidgate exploit kit campaign stopped distributing CryptXXX and now delivers the .zepto Locky variant exclusively through Neutrino EK since July 2016.

By mid-July 2016, the Afraidgate campaign switched from CryptXXX ransomware to consistently delivering the .zepto (Zepto) variant of Locky, using the Neutrino exploit kit after Angler EK disappeared in early June 2016. The campaign starts from compromised websites with injected scripts that redirect to Afraidgate domains and then Neutrino EK landing pages on .top domains. Zepto emerged after the Necurs botnet returned from a three-week outage, bringing new anti-sandboxing and evasion techniques.

Palo Alto Unit 42 · Aug 17, 2026Ransomware in the wild