Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef40cf1770917edc…

MALICIOUS

PDF

43.5 KB Created: 2021-05-13 15:36:07 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-16
MD5: b03895a4eab484b82ef4de6a8cf2fbfc SHA-1: 362dfde9e7e75d9626025d0e31e929d8dd6482f3 SHA-256: ef40cf1770917edcdedfbff4071dee0eb6f72c2cd2db01ff5a87686db8dadc7e
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to known malicious redirectors and lures users with themes like 'game hacks' and 'free Robux'. The document body and heuristics indicate a clear intent to redirect users to potentially harmful websites. While no scripts were explicitly extracted, the PDF structure itself facilitates these malicious redirects, aligning with T1566.001 (Spearphishing Attachment) as a likely initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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.xyz/app/431946152/instant-robux-game-hack In PDF document text
    • http://zercalo.org/images/minecraft-java-code-free_GM479516143.pdfIn PDF document text
    • http://zercalo.org/images/is-roblox-free-on-nintendo-switch_GM431946152.pdfIn PDF document text
    • http://zercalo.org/images/40-free-spins-coin-master_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/free-draw-2-roblox_GM431946152.pdfIn PDF document text
    • http://zercalo.org/images/how-to-get-free-minecraft-windows-10_GM479516143.pdfIn PDF document text
    • http://zercalo.org/images/coin-master-rewards-app_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/coin-master-free-spins-daily-fb-champion_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/free-coins-coin-master-daily_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/try-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/coin-master-free-spins-hack-link_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/roblox-hacked-com-2021_GM431946152.pdfIn PDF document text
    • http://zercalo.org/images/minecraft-online-free-no-download_GM479516143.pdfIn PDF document text
    • http://zercalo.org/images/coin-master-mod_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/how-to-hack-roblox-on-mobile_GM431946152.pdfIn PDF document text
    • http://zercalo.org/images/minecraft-free-version_GM479516143.pdfIn PDF document text
    • http://zercalo.org/images/lazyblocks-com-free-robux_GM431946152.pdfIn PDF document text
    • http://zercalo.org/images/minecraft-free-download-mac_GM479516143.pdfIn PDF document text
    • http://zercalo.org/images/coin-master-free-spins-save_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/how-to-get-free-spins-on-coin-master-2021-iphone_GM406889139.pdfIn PDF document text
    • http://zercalo.org/images/roblox-svg-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
stream_003_off00004814.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4814 28016 bytes
SHA-256: d10d6f80e8974a14461fcf0ce6441bf8702d0f4e016e60aa6d0e7198485bbbab
font_01_sfnt_off000087fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x87FD 18184 bytes
SHA-256: 234f9e95fa1241feb438ae0efba81c56d05ba2863eb0b0d090bdd6eb60e49a51

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