Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b57feed342e92e7…

MALICIOUS

PDF

46.3 KB Created: 2021-06-08 23:04:51 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 85df7a6efc521bd782d48d8765fa4f0e SHA-1: e7702146cc3bd6e6ceb4ada24270231d77a72f4f SHA-256: 9b57feed342e92e729b2aff0bf5582d1fcb4d21f0b9eb45198670a5bfb506eea
240 Risk Score

Malware Insights

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

The PDF document contains multiple links to redirectors and game hack lures, impersonating brands like Facebook to trick users. The presence of a fake CAPTCHA heuristic suggests an attempt to trick users into executing further actions, likely leading to credential harvesting or malware download. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly indicate a phishing or social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9810

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
  • Brand-impersonation credential phishing lure high SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: call-to-action link host does not match the impersonated brand: https://netcdn.tw/app/431946152/free-robux-robuxking-game-hack.
  • 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/free-robux-robuxking-game-hack In PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/coin-master-hacks-android_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/robux-claimer_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/rbxfree-com-free-robux_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/free-roblox-executor-no-key_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/coin-master-free-link-spin_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/free-robux-wheel_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/minecraft-hacks-xbox-one_GM479516143.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/como-ser-hacker-en-roblox-skywars_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/rbx-free_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/daily-coin-master-free-spin-apk_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/how-to-hack-in-arsenal_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/how-to-hack-coin-master-cheat-engine_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/free-coins-coin-master-no-human-verification_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/coin-master-spin-link-free_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/coin-master-hack-no-human-verification-2021_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/free-coin-master-spins-2021-link_GM406889139.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/minecraft-free-apk_GM479516143.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/how-to-hack-roblox-to-get-robux_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/fkrepository/repository/how-do-you-earn-robux_GM431946152.pdfIn PDF document text
    • http://elibraryfk.unjani.ac.id/elibrary/repository/earn-roblox_GM431946152.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005212.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5212 23548 bytes
SHA-256: de598cd6cd73184d7054e74ac219c820f1c18f7cb46a852045122460bc1668af
font_01_sfnt_off0000876b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x876B 2844 bytes
SHA-256: baad2f3f6808f4af03fa9398e38c580c8d846f7f773a947d8cc1f39b2753d31a
font_02_sfnt_off0000912d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x912D 18592 bytes
SHA-256: d03b66a19e8e39d54ab798c2bbaa8177a4639bc210c2fd75bed78a26782ad476