Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c3a12533470911d…

MALICIOUS

PDF

45.8 KB Created: 2021-06-03 11:14:03 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 6faf6f8b169268114ed08dc5badc667a SHA-1: 5d719b75897528954c484fc4ea9cbd2a84964622 SHA-256: 6c3a12533470911d2602cb2bfdab99eb3409eb3fdb6be1bd0259e994011e2596
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious Link

The PDF contains a critical heuristic firing for a malicious redirector link, specifically pointing to a 'free Robux' or 'game hack' lure. The document body and embedded URLs reinforce this theme, suggesting the primary goal is to trick users into visiting a malicious site. The malformed stream length and ML classifier also indicate malicious intent, likely related to exploiting PDF vulnerabilities to redirect the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9890

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.
  • 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
  • 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 https://netcdn.online/app/431946152/free-robux-no-password-game-hack In PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/como-hackear-coin-master-espaol_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-spin_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/www-roblox-com-robux_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-pet-food-for-coin-master_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-master-free-coins-generator_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/op-rewards-robux_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-master-link_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/how-to-get-minecraft-for-free-on-nintendo-switch_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/is-minecraft-free-on-xbox_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/minecraft-hacked-apk_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-roblox-accounts-2021_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/make-free-robux_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-master-free-2021-spin-link_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/free-robux-hack_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/roblox-group-free-robux_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/robuxy-com-free-robux_GM431946152.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/coin-master-daily-free-spins-link-today_GM406889139.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/pokemon-go-free-items_GM1094591345.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/minecraft-survival-free_GM479516143.pdfIn PDF document text
    • https://www.polresbadung.id/new/public/ckfinder/userfiles/files/get-free-spins-coin-master-2021_GM406889139.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_004_off000052b3.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x52B3 26508 bytes
SHA-256: 8daa21eb3b628d7bbb114d111bee6fc7b6f642150346f19c04a60f4974195fdb
font_01_sfnt_off00008ef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8EF1 18732 bytes
SHA-256: b254955316d184f98c6f6070526605807868e3146c8b9e5f8ca39f20861b2296