Malware

CostaBricks

CostaBricks is a custom Windows malware associated with the CostaRicto intrusion set. It is part of a bespoke toolset that has been used alongside other CostaRicto malware, including SombRAT and PS1. Publicly documented behavior shows that CostaBricks uses bytecode-based decryption to reveal embedded payloads at runtime, helping conceal its functionality until execution. It also employs a custom virtual-machine-style obfuscation mechanism to complicate analysis and hinder reverse engineering. CostaBricks is capable of injecting a payload directly into the memory of a compromised host, indicating use as an in-memory execution component and a defense-evasion mechanism. Reported API usage includes memory allocation and dynamic loading functions consistent with unpacking, runtime resolution, and payload execution. Available information supports characterization of CostaBricks as a custom loader used in targeted intrusions by CostaRicto against Windows systems.

For your environment

Hunt this family in your stack

Mallory pivots from this family to the IOCs, detections, and named campaigns that touch your stack, and pages you when something new lands.

Start free trial

MITRE ATT&CK

Techniques & procedures

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

Execution

1 technique

T1106Native APIEvidence1

Privilege Escalation

1 technique

T1055Process InjectionEvidence5

The content repeatedly describes malware and threat actors injecting shellcode, DLLs, or payloads into legitimate processes such as svchost.exe, explorer.exe, iexplore.exe, cmd.exe, lsass.exe, and browser processes.

Stealth

4 techniques

T1027.001Binary PaddingEvidence1

T1027.002Software PackingEvidence2

"Sandworm Team used UPX to pack a copy of Mimikatz"; "APT38 has used several code packing methods such as Themida, Enigma, VMProtect, and Obsidium"; "Lazarus Group packed malicious .db files with Themida to evade detection."

T1055Process InjectionEvidence5

T1140Deobfuscate/Decode Files or InformationEvidence5

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.

Command and Control

1 technique

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

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

12 SOURCESView more in app

mitre attack websiteNews

Apr 25, 2023

Process Injection, Technique T1055 - Enterprise | MITRE ATT&CK®

Malware capable of injecting a payload into memory on a compromised host.

mitre attack websiteNews

Oct 21, 2021

Updates - Updates - October 2021 | MITRE ATT&CK®

Enterprise New Software: ... CostaBricks

mitre attack websiteNews

Oct 21, 2021

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

Malware that uses bytecode to decrypt embedded payloads.

mitre attack websiteNews

Aug 7, 2017

Process Injection, Technique T1055 - Enterprise | MITRE ATT&CK®

Malware capable of injecting payloads into memory on compromised hosts.

+8 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets match these IOCs, which detections are missing, which campaigns to expect next, and what to do in the next 30 minutes.

Start free trial

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 mapping6

Every documented technique, ranked by evidence weight.

Researcher chatter

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

CostaBricks