Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b81d92ca1dab787…

MALICIOUS

PDF

50.2 KB Created: 2021-06-03 11:14:33 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 8b90aed8a9b68dfa00d05ef8cffe502f SHA-1: ec69c1f1747ead6b533d399b2439bfd803893aaa SHA-256: 1b81d92ca1dab78793089b6f818d71ed8fecda33836ff89157848960037d90a6
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains a lure for free Roblox accounts with Robux, a common social engineering tactic. It embeds a URL that likely leads to the download of a second-stage payload. The ML classifier also flagged this PDF as malicious with a high confidence score.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9789

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.online/app/431946152/free-roblox-accounts-with-robux-that-work-not-banned-2021-game-hack In PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-robux-hacks-no-verification_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/robux-in_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-master-hack-https-coinms-net_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/how-to-get-free-robux-with-no-verification_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/roblox-games-with-free-boombox_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-draw-roblox_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/how-to-get-free-robux-2021-easy_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/minecraft-free-download-pc_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/how-to-hack-someones-account-on-roblox_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/robux-com-free_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/robux-boost_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/cute-free-stuff-on-roblox_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-robux-generator-codes_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/can-you-make-a-minecraft-server-for-free_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-roblox-hack_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/how-do-you-get-free-food-in-coin-master_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/minecraft-windows-10-hacks_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/best-way-to-hack-coin-master_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-master-free-daily-spins-link-2021_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/minecraft-pocket-apk_GM479516143.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off000055f6.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x55F6 25480 bytes
SHA-256: 01affec4432b2b17f707d1b87329eb1284c059ff038427e7379e3929030e1a31
font_01_sfnt_off00009092.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9092 5696 bytes
SHA-256: 450e3ee45915afe13702bf1d587eb8b9ad88a8d2113419ac9f2fd116a828e139
font_02_sfnt_off00009da4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9DA4 19652 bytes
SHA-256: 72c791ad1c4340ed85ac0ecdba514e35635851f3f818d4a167a4eafc97bf1d2a