Malware

WeaselBiscuit

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.

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MITRE ATT&CK

Techniques & procedures

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

Initial Access

1 technique

T1195.002Compromise Software Supply ChainEvidence1

“a cluster of 13 npm packages ... have been found to deliver a previously undocumented JavaScript stealer codenamed WeaselBiscuit.”

Execution

1 technique

T1059.007JavaScriptEvidence1

“it's triggered via an npm import, which causes the loader (‘loader.js’) to pull the main malware ... and execute it directly in memory.”

Stealth

1 technique

T1620Reflective Code LoadingEvidence1

“pull the main malware from an Npoint dead drop and execute it directly in memory.”

Credential Access

1 technique

T1056.001KeyloggingEvidence1

“Based on operator commands received from the C2 server ... it can also log ... keystrokes on Windows machines.”

Discovery

2 techniques

T1016System Network Configuration DiscoveryEvidence1

“The use of nested public-IP and geolocation lookup via api.ipify.org and ip-api.com.”

T1082System Information DiscoveryEvidence1

“Upon execution, it resolves its command-and-control (C2) configuration ... profiles the compromised host.”

Collection

3 techniques

T1005Data from Local SystemEvidence1

“It uploads every readable, nonempty file under the extension's Local Extension Settings directory — a raw LevelDB key/value store — wholesale.”

T1056.001KeyloggingEvidence1

“Based on operator commands received from the C2 server ... it can also log ... keystrokes on Windows machines.”

T1115Clipboard DataEvidence1

“Based on operator commands received from the C2 server ... it can also log clipboard contents ... on Windows machines.”

Command and Control

1 technique

T1102Web ServiceEvidence1

“the loader (‘loader.js’) [pulls] the main malware from an Npoint dead drop” and “resolves its command-and-control (C2) configuration from a separate Npoint URL.”

INDICATORS OF COMPROMISE

IOCs tracked for this family

2 indicators attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.

View more in app

Network

2 tracked

IPs, domains, and DNS infrastructure linked to this family.

TypeValueLatest sighting

domain●●●●●●●●●●●●View more in apptoday

ip.v4●●●●●●●●●●●●View more in apptoday

ACTIVITY FEED

Recent activity

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

2 SOURCESView more in app

the hacker newsNews

Sep 18, 2026

WeaselBiscuit Stealer Spreads via 13 npm Packages to Harvest Chrome Extension Storage

A previously undocumented JavaScript information stealer distributed through malicious npm packages. It profiles hosts, exfiltrates Chrome extension Local Extension Settings/LevelDB data on Windows, macOS, and Linux, and can log clipboard contents and keystrokes on Windows based on C2 commands. It lacks persistence, remote access, wallet-draining functionality, and secondary-payload delivery.

lazarusholic blueskyNews

Sep 17, 2026

Post by @lazarusholic.bsky.social - Bluesky

The referenced post identifies WeaselBiscuit as the primary malware/tool being discussed, but provides no technical behavior details.

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.

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IOC matching2

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 mapping9

Every documented technique, ranked by evidence weight.

Researcher chatter

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

Back to malware

Malware

WeaselBiscuit

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

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

Initial Access

1 technique

T1195.002Compromise Software Supply ChainEvidence1

“a cluster of 13 npm packages ... have been found to deliver a previously undocumented JavaScript stealer codenamed WeaselBiscuit.”

Execution

1 technique

T1059.007JavaScriptEvidence1

“it's triggered via an npm import, which causes the loader (‘loader.js’) to pull the main malware ... and execute it directly in memory.”

Stealth

1 technique

T1620Reflective Code LoadingEvidence1

“pull the main malware from an Npoint dead drop and execute it directly in memory.”

Credential Access

1 technique

T1056.001KeyloggingEvidence1

“Based on operator commands received from the C2 server ... it can also log ... keystrokes on Windows machines.”

Discovery

2 techniques

T1016System Network Configuration DiscoveryEvidence1

“The use of nested public-IP and geolocation lookup via api.ipify.org and ip-api.com.”

T1082System Information DiscoveryEvidence1

“Upon execution, it resolves its command-and-control (C2) configuration ... profiles the compromised host.”

Collection

3 techniques

T1005Data from Local SystemEvidence1

“It uploads every readable, nonempty file under the extension's Local Extension Settings directory — a raw LevelDB key/value store — wholesale.”

T1056.001KeyloggingEvidence1

“Based on operator commands received from the C2 server ... it can also log ... keystrokes on Windows machines.”

T1115Clipboard DataEvidence1

“Based on operator commands received from the C2 server ... it can also log clipboard contents ... on Windows machines.”

Command and Control

1 technique

T1102Web ServiceEvidence1

“the loader (‘loader.js’) [pulls] the main malware from an Npoint dead drop” and “resolves its command-and-control (C2) configuration from a separate Npoint URL.”

INDICATORS OF COMPROMISE

IOCs tracked for this family

2 indicators attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.

View more in app

Network

2 tracked

IPs, domains, and DNS infrastructure linked to this family.

TypeValueLatest sighting

domain●●●●●●●●●●●●View more in apptoday

ip.v4●●●●●●●●●●●●View more in apptoday

ACTIVITY FEED

Recent activity

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

2 SOURCESView more in app

the hacker newsNews

Sep 18, 2026

WeaselBiscuit Stealer Spreads via 13 npm Packages to Harvest Chrome Extension Storage

lazarusholic blueskyNews

Sep 17, 2026

Post by @lazarusholic.bsky.social - Bluesky

The referenced post identifies WeaselBiscuit as the primary malware/tool being discussed, but provides no technical behavior details.

What this page doesn’t show

The version that knows your environment.

Start free trial

IOC matching2

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 mapping9

Every documented technique, ranked by evidence weight.

Researcher chatter

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