Malware

YAHOYAH

YAHOYAH is a malware family that uses HTTP for command-and-control communications, performs security software discovery by checking for antimalware processes on infected systems, and decrypts downloaded files before executing them. Its observed behavior indicates a staged execution model in which additional payloads are retrieved, decrypted, and then launched, while host-side checks for defensive products support evasion and execution decisions. The combination of payload decryption, antimalware process discovery, and web-based C2 suggests use as a post-compromise implant or loader on Windows systems.

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MITRE ATT&CK

Techniques & procedures

7 distinct techniques documented for this family, organized by ATT&CK tactic.

Stealth

3 techniques

T1027Obfuscated Files or InformationEvidence5

The content repeatedly describes payloads, strings, configuration files, scripts, URLs, and binaries being obfuscated or encoded using Base64, XOR, RC4, AES, RSA, hex encoding, custom algorithms, and other methods across many malware families and threat actors.

T1027.013Encrypted/Encoded FileEvidence1

T1140Deobfuscate/Decode Files or InformationEvidence8

The content is a long ATT&CK-style listing of malware and threat groups that 'decrypt', 'decode', 'deobfuscate', 'unpack', or 'decompress' payloads, strings, configuration data, shellcode, and files prior to execution or use.

Discovery

2 techniques

T1082System Information DiscoveryEvidence9

The content repeatedly describes malware and threat actors collecting OS version, computer name, architecture, CPU, memory, disk, language, and other host details; examples include use of commands such as ver, systeminfo, hostname, uname -m, sw_vers -productVersion, and fsutil.

T1518.001Security Software DiscoveryEvidence3

Adversaries may attempt to get a listing of security software, configurations, defensive tools, and sensors that are installed on a system or in a cloud environment.

Command and Control

2 techniques

T1071.001Web ProtocolsEvidence5

The content is a long ATT&CK-style listing showing numerous malware families and threat groups that 'use HTTP,' 'use HTTPS,' 'HTTP POST requests,' 'HTTP GET requests,' or 'HTTP/S' for command and control communications.

T1105Ingress Tool TransferEvidence2

The content repeatedly describes malware and threat actors that can "download files from C2," "download additional payloads," "upload and download files," "retrieve payloads from the C2 server," and "copy files to remote machines."

ACTIVITY FEED

Recent activity

9 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

9 SOURCESView more in app

mitre attack websiteNews

Oct 21, 2021

Deobfuscate/Decode Files or Information, Technique T1140 - Enterprise | MITRE ATT&CK®

Malware that decrypts downloaded files before execution.

mitre attack websiteNews

Jan 1, 2021

Deobfuscate/Decode Files or Information, Technique T1140 - Enterprise | MITRE ATT&CK®

Malware that decrypts downloaded files prior to execution.

mitre attack websiteNews

Mar 7, 2018

Software Discovery: Security Software Discovery, Sub-technique T1518.001 - Enterprise | MITRE ATT&CK®

Malware that checks for antimalware processes on the system.

mitre attack websiteNews

Mar 7, 2018

Software Discovery: Security Software Discovery, Sub-technique T1518.001 - Enterprise | MITRE ATT&CK®

Malware that checks for antimalware processes on the system.

+5 more in the timeline

What this page doesn’t show

The version that knows your environment.

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IOC matching

Match every observed IP, domain, and hash against your live telemetry.

Threat actor attribution

Named campaigns wielding this family, with evidence pinned to each claim.

Exploited vulnerabilities

CVEs this family uses for access and lateral movement.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

MITRE ATT&CK mapping7

Every documented technique, ranked by evidence weight.

Researcher chatter

Reddit, Mastodon, and CTI community discussion around this family.

YAHOYAH