Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c883e660e8439d3…

MALICIOUS

PDF

35.1 KB Created: 2021-07-05 13:01:13 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 422eb59b159c612a781d23185bd7b237 SHA-1: e4f52e4d5a5138b32cd28107015e7039b2d22124 SHA-256: 9c883e660e8439d332037bbe896c9f3df4dbaf2944e6a35f64ca45aef28eb2e6
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains multiple embedded links that redirect to malicious infrastructure, specifically promoting 'free Robux' or game hacks. The ML classifier strongly flagged this PDF as malicious, and heuristics indicate it uses a redirector lure. While no scripts were extracted, the document's structure and embedded URLs strongly suggest a phishing or scam attempt designed to lead users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://netcdn.tw/app/431946152/free-robux-please-game-hack In PDF document text
    • http://achauco.vn/public/upload/files/how-to-get-robux-for-free-2021_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/how-to-get-free-robux-2021-no-human-verification_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-robux-codes-generator-no-verification_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/roblox-free-robux-every-5-seconds_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/minecraft-hacker-mask_GM479516143.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/coin-master-daily-free-spins-hack_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-tiktok-fans-no-human-verification-or-downloading-apps_GM835599320.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-spins-coin-master-unlimited_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/coin-master-100-spin_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/how-do-you-download-minecraft-for-free_GM479516143.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/pokemon-go-free-or-not_GM1094591345.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/roblox-arsenal-hack_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/wish-free-robux_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/fly-cheat-2021-roblox_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-robux-without-verification_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-robux-with-no-survey_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/how-to-downgrade-minecraft-pe_GM479516143.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/can-you-get-free-robux-on-roblox_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/black-jacket-with-blue-shirt-roblox-free_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/claimrbx-free-robux_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_off000031ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x31BA 22808 bytes
SHA-256: c20e9713893ec4d37a36d016e7d50405f64ecbc570d546b03773e1e5eb7826fd
font_01_sfnt_off0000648f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x648F 18944 bytes
SHA-256: febdc7d9b58a8f5ce5dc5375b2c9cd11fa7fa1fbf09dd55f49548e64a33317d8