Malicious PDF — malware analysis report

Static analysis result for SHA-256 988c5dc479ba34ef…

MALICIOUS

PDF

36.0 KB Created: 2021-07-05 23:05:48 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2026-06-04
MD5: 815c0806f25949c5785434d06958fdb5 SHA-1: 09a343e2943c7091b13e99c572721618aac0c504 SHA-256: 988c5dc479ba34effb213336075153f5337a4307021a323888c6dc631327c77d
180 Risk Score

Malware Insights

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

The PDF contains a lure for 'free Robux' and game hacks, directing users to a known malicious redirector. The document body and embedded URLs reinforce this social engineering tactic. The malformed stream length and ML classifier indicate a malicious PDF, likely exploiting a vulnerability to redirect the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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.tw/app/431946152/free-robux-websites-no-human-verification-game-hack In PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/free-spins-coins-coin-master_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/how-do-you-get-free-robux-without-paying_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/how-to-get-free-robux-not-a-scam_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/free-robux-websites-that-actually-work_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/how-to-play-minecraft-with-friends-for-free_GM479516143.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/robux-2021_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/microsoft-free-robux_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/coin-master-hack-without-verification-for-iphone_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/royale-high-roblox-hacks_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/roblox-shirts-free-free-shipping_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/dungeon-life-roblox-cheat-codes_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/roblox-april-fools-hack_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/coin-master-cheat-to-get-free-spins_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/spins-coin-master_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/free-downloads-for-coin-master-daily-rewards_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/robux-com-free-robux_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/coin-master-online-hack-download_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/roblox-how-to-get-free-robux-without-cheat-engine_GM431946152.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/links-to-get-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • http://smagripadps.sch.id/new/public/ckfinder/userfiles/files/how-to-hack-a-minecraft-server-and-make-yourself-op_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_off00003479.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3479 22368 bytes
SHA-256: ca0062e7b0c4116479502b3bea5d35df05355ee063a963aa27b4f42e6d6faa9a
font_01_sfnt_off00006659.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6659 19532 bytes
SHA-256: e3099c9d0ccbc2ba8291647bb1da8d0e7f9f445102052ab388bc51958bf10930