Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b4345acdfec377…

MALICIOUS

PDF

34.4 KB Created: 2021-06-23 22:42:54 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 19b77489a679735326840e9420c9b4ff SHA-1: 30936177c57a7c5b8630ceefa769cc79a3245cda SHA-256: 21b4345acdfec3774ab82076148d3fafb33ae0fc0ec96532073c65fcb0b99897
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are SEO-optimized to appear as legitimate resources for game-related cheats and currency. The primary lure is 'free Robux', a common theme in phishing and scam campaigns. The document's structure and the high number of outbound links suggest it functions as a link farm designed to redirect users to potentially malicious sites or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • PDF links to a 'free generator / game hack' redirector high PDF_GAME_HACK_REDIRECT_LURE
    PDF's clickable action targets a redirector of the form /app/<id>/<slug>-game-hack — the landing-page shape of a large SEO 'free spins / generator / game hack' lure family that funnels victims through rotating disposable hosts to a malware/scam payload. The multi-link variants also trip ML/link-farm rules; this catches the single-link variants that otherwise score clean.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • External URI info PDF_URI
    PDF contains an external URL action
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://netcdn.co/app/431946152/free-robux-group-game-hack PDF link annotation
    • https://elearning.madhpku.com/__statics/gudangsoal/files/woman-roblox_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/coin-master-free-spins-today-new_GM406889139.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/pokemon-go-free-apk-download_GM1094591345.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/howto-get-free-robux-new-2021_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/free-robux-no-verification-or-survey_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/roblox-login-hack_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/how-to-make-a-free-robux-game-v3rmillion_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/how-to-get-free-robux-not-a-scam_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/como-sacar-buen-puntaje-en-juego-coin-master-free-spins_GM406889139.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/how-to-hack-roblox-to-get-robux_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/free-printable-roblox-images_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/how-to-speedhack-roblox-with-cheat-engine_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/roblox-play-now-for-free-unblocked_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/free-coins-and-spins-coin-master_GM406889139.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/coin-master-spin-free_GM406889139.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/get-me-free-robux_GM431946152.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/coin-master-free-spin-app-reviews_GM406889139.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/minecraft-education-edition-free_GM479516143.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/free-coins-coin-master-blog_GM406889139.pdfIn PDF document text
    • https://elearning.madhpku.com/__statics/gudangsoal/files/roblox-bundles-free_GM431946152.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00002eb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2EB3 22796 bytes
SHA-256: e52882a13da1a42d15bce61a885629e0ecbb777d61b1103459c53a3c010695e0
font_01_sfnt_off000061af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x61AF 18892 bytes
SHA-256: 67507f51078b9d360364fd80bede771b0831b8cadce387b59c9348d966d9fcb5

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