Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bf481c199b46e5b…

MALICIOUS

PDF

44.7 KB Created: 2021-06-09 16:48:24 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 7b9b25e969d6f3e081114b1183a78ebf SHA-1: 852ddecc040af1d3149f33f5ff7aff0dc9b68d0c SHA-256: 3bf481c199b46e5bb06056aec9f068f946217ac034a14ab0babbf59bcf23a744
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a critical heuristic firing for a malicious redirector link, specifically pointing to a lure for game hacks and free generators. The embedded URL, https://netcdn.tw/app/431946152/roblox-codes-for-robux-free-game-hack, is identified as malicious infrastructure. The document body, though heavily obfuscated, contains references to 'Roblox Codes For Robux Free' and the same URL, reinforcing the lure. The ML classifier also flagged this PDF with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

Heuristics 4

  • PDF links to a 'free generator / game hack' redirector critical 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. CRITICAL on its own: the /app/<id>/<slug>-game-hack path shape is unambiguous scam infra, and the host rotates so a host-list match can't be relied on.
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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
  • 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 https://netcdn.tw/app/431946152/roblox-codes-for-robux-free-game-hack In PDF document text
    • http://library.fisip.upnvj.ac.id/repository/coin-master-free-spins-link_GM406889139.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/coin-master-game-free-download_GM406889139.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/master-free-spins-and-coins_GM406889139.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/coin-master-free-spins-daily_GM406889139.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/tiktok-minecraft-hacks_GM479516143.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-roblox-accounts-with-robux-that-work-not-banned_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/roblox-how-to-noclip-cheat-engine-feb-2021-mac-apple_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-roblox-hair-codes_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/games-that-can-be-hacked_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/minecraft-hacks-xbox-one_GM479516143.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-roblox-groups-with-funds_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/coin-master-free-spins_GM406889139.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/how-to-hack-roblox-accounts-on-mobile_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-robux-without-verification_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-robux-com-real_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/actual-free-robux_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-robux-no-downloading-apps_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/free-robux-no-survey-no-download-2021-no-human-verification_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/roblox-girl_GM431946152.pdfIn PDF document text
    • http://library.fisip.upnvj.ac.id/repository/minecraft-building-hacks_GM479516143.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
stream_004_off00005082.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5082 26144 bytes
SHA-256: 1afafbd5de5394c8c0d919f09f6c81cb68a1d8833be0e06f2889e1abcb7f8a58
font_01_sfnt_off00008c24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8C24 18260 bytes
SHA-256: 9e1dbc629a4453adfadc5044bc77c842f77e4788231e2298fe155e7d8301ab5b

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