Malicious PDF — malware analysis report

Static analysis result for SHA-256 c31ac89c3a0c0d96…

MALICIOUS

PDF

48.5 KB Created: 2021-06-03 05:19:33 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 5b64e40808c33edd2e38812207e3f3b7 SHA-1: 0bdd3cd44199db91bbcf509ad5f8c6138e8b4169 SHA-256: c31ac89c3a0c0d960b8b155d797aefcfeea2a1b10665ac3504bd34aff8728b53
260 Risk Score

Malware Insights

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

This PDF document employs a fake CAPTCHA lure to trick users into clicking malicious links, disguised as 'free Robux' or 'game hacks'. The document contains numerous links to external sites, including a known malicious redirector, suggesting an attempt to drive traffic to potentially harmful content or exploit kits. The presence of embedded URLs and the overall structure strongly indicate a phishing or scamming attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9796

Heuristics 6

  • 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.
  • 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.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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-robux-websites-that-actually-work-2021-game-hack In PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-game-free-play-online_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/free-robux-with-no-human-verification_GM431946152.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/how-to-get-robux-for-free-2021_GM431946152.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/minecraft-tiktok-hacks_GM479516143.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/free-spin-coin-master-game_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/op-rewards-robux_GM431946152.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/robux-generator-no-verification-needed_GM431946152.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/how-to-get-free-coins-on-coin-master_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/free-robux-accounts-2021_GM431946152.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-hacks-to-get-spins_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coinmaster-free-cards_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-free-link-2021_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/free-robux-apk_GM431946152.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-guide-to-free-spins-and-rewards_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-rewards-app_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/free-coins-and-spins-link-for-coin-master_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/how-to-download-minecraft-for-free-on-your-phone_GM479516143.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-free-spin-link-today-download_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/coin-master-free-spins-2021_GM406889139.pdfIn PDF document text
    • http://www.library.umbjm.ac.id/repository/free-spins-coin-master-hack-2021_GM406889139.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
font_00_sfnt_off0000541e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x541E 24916 bytes
SHA-256: 33a9f206c3230fe6c2d478023aeb25a2f86107cbe63b00616c41869b4271c426
font_01_sfnt_off00008cdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8CDF 2824 bytes
SHA-256: 1d0cb1023eaa225682b8e7a2c8df4e4c96545ba7eedaf3d9844e51183e9ca189
font_02_sfnt_off0000968b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x968B 19656 bytes
SHA-256: 7b3ca8e33f6ab65cae0b12a773bae5d0e0377a7b1030ef9ec14be3c3cdd71d54

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