Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fbf2980f2a9bc1c…

MALICIOUS

PDF

35.6 KB Created: 2021-06-27 01:37:58 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 9946efba102bab7f5b99680b69384df1 SHA-1: 5cd6c44f23e729c8f1156177d052aadc9fcb3df4 SHA-256: 4fbf2980f2a9bc1cc40f4d07f0cf108aaf23c598523eb323caa6f819f519da5a
180 Risk Score

Malware Insights

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

The PDF contains a lure for a "free Robux hack" which links to a known malicious redirector. The ML classifier strongly indicates maliciousness, and the malformed stream suggests an exploit attempt. The document body and embedded URLs reinforce the theme of game hacks and free currency, aiming to trick users into clicking the malicious link.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.co/app/431946152/free-robux-hack-no-human-verification-and-no-download-game-hack In PDF document text
    • http://lib.teknik.unimal.ac.id//repository/coin-master-free-spins-and-coins-2021_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/roblox-counter-blox-hacks-2021-download_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/pokemon-go-free-roam_GM1094591345.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/how-to-get-100-robux-for-free_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/coin-master-online-hack-link_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/haktuts-coin-master_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/bloxland-earn-free-robux_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/free-roblox-premium_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/robux-hack-fast-and-easy_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/download-coin-master-apk-hacked_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/roblox-hack-tool_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/free-daily-spins-coin-master_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/roblox-hack-robux-2021-subscribe_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/coin-master-gift-link_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/can-you-really-hack-coin-master-ios_GM406889139.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/minecraft-games-free-download_GM479516143.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/roblox-hack-codes_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/free-robux-easy_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id//repository/how-to-hack-in-roblox-prison-life_GM431946152.pdfIn PDF document text
    • http://lib.teknik.unimal.ac.id/repository/how-to-get-minecraft-for-free-on-ps4-2021_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
font_00_sfnt_off000031ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x31AB 22228 bytes
SHA-256: 6d60b48ff0cbf5886718cb99a1129fd3db6610ddd3aaa28cf3b6b2cf0d0ea77d
font_01_sfnt_off0000633d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x633D 20084 bytes
SHA-256: 159bb30daae4f959840fdc2f6b3c355e6b7b8ce2e7d24961fa28fdb711523475

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