Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a375546c23adf0…

MALICIOUS

PDF

49.0 KB Created: 2021-06-10 14:26:56 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 404e6f8306a714ee3b8823d3f972f925 SHA-1: f258b15dda93a286fc6d1b547843b0eab00eaef4 SHA-256: 13a375546c23adf06fce8adb41e9c506b531235cc3319146be2047f553b7cf21
220 Risk Score

Malware Insights

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

The PDF document contains multiple links to redirectors and game hack lures, aiming to trick users into a fake CAPTCHA page. The ML classifier also flagged this PDF as malicious. The document body text and embedded URLs suggest a social engineering attempt to lead users to potentially malicious content or further exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9871

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
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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.tw/app/431946152/how-to-get-free-robux-items-game-hack In PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/how-to-get-coins-on-tiktok-for-free_GM835599320.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/roblox-speed-hack_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/coin-master-free-spin-app-apk_GM406889139.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/coin-master-event-hack_GM406889139.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/spin-coin-master_GM406889139.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/free-robux-com-real_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/how-to-hack-roblox-accounts-on-phone-2021_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/roblox-promo-codes-for-free-robux_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/free-robux-without-downloading-anything_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/give-free-robux_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/robux-free-robux-generator-no-human-verification_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/minecraft-story-mode-free-download_GM479516143.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/how-to-download-wurst_GM479516143.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/coin-master-heaven-free-spins_GM406889139.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/free-t-shirt-roblox_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/free-robux-generator-no-survey_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/how-to-get-free-spins-on-coin-master-facebook_GM406889139.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/can-you-actually-get-free-robux_GM431946152.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/minecraft-java-edition-free-download-for-android_GM479516143.pdfIn PDF document text
    • https://digilib.stikesindramayu.ac.id/repository/free-robux-no-generator_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_004_off000055e6.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x55E6 31332 bytes
SHA-256: 18efe3c82d72ce590fcf0ea4d61626359121b02e7532cfc9f7a3c3ae7fb514f6
font_01_sfnt_off00009cb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9CB7 18544 bytes
SHA-256: f62ccd19852b7ab1e87a79c4c89302c13d74f4c6bf3bf4251cb35a6c50c24621

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