FastSpy
FastSpy is a malware family associated with the North Korea-aligned Kimsuky espionage activity cluster. Reporting cited in the source material places FastSpy among updated malware used by Kimsuky in 2022, alongside FastFire, FastViewer/FireViewer, Sharpext, BabyShark, KONNI, ReconShark, KimJongRAT, and Kimsuky RAT. The content notes similar behavior observed in a FastSpy infection chain, but does not provide detailed technical functionality or specific indicators of compromise for FastSpy itself. Based on the supporting content, FastSpy is linked to Kimsuky’s broader spearphishing-driven intrusion activity targeting NGOs, think tanks, diplomatic agencies, military organizations, economic groups, research entities, and organizations involved in North Korean policy and relations, with targeting spanning South Korea, the United States, Japan, and other countries. Kimsuky operations described in the content use socially engineered lures, typosquatting or theme-aligned domains, and malicious document delivery mechanisms including HWP, Microsoft Word, and PDF files. The source also attributes to Kimsuky the use of IP validation, geofencing in KONNI RAT delivery, and selective file exfiltration based on remote file lists, but these behaviors are not explicitly tied to FastSpy specifically.
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.
Groups observed using it
2 distinct threat actors attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
Tools BabyShark, KONNI, FastFire, FireViewer, FastSpy, ReconShark, KimJongRAT, Kimsuky
Techniques & procedures
5 distinct techniques documented for this family, organized by ATT&CK tactic.
Resource Development
1 technique"...using typosquatting or domains thematically aligned with their target."
Initial Access
2 techniques"The threat actors conduct extensive spearphishing operations, using typosquatting or domains thematically aligned with their target."
"...often involves malicious Hangul Word Processing (HWP) documents as a delivery mechanism... evolved its capabilities to include... Microsoft Word and PDF documents."
Stealth
1 techniqueFor instance, Kimsuky was recently observed using an IP validation method as part of its GoldDragon infection mechanism. The same Intrusion Set also newly implemented a geofencing mechanism in their signature malware Konni RAT, and similar behaviour was observed in the FastSpy infection chain.
Discovery
2 techniquesFor instance, Kimsuky was recently observed using an IP validation method as part of its GoldDragon infection mechanism. The same Intrusion Set also newly implemented a geofencing mechanism in their signature malware Konni RAT, and similar behaviour was observed in the FastSpy infection chain.
The same Intrusion Set also newly implemented a geofencing mechanism in their signature malware Konni RAT, and similar behaviour was observed in the FastSpy infection chain.
Recent activity
2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Android malware/infection chain associated with Kimsuky exhibiting geofencing-like behavior.
Tools BabyShark, KONNI, FastFire, FireViewer, FastSpy, ReconShark, KimJongRAT, Kimsuky
The version that knows your environment.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.