Malicious PDF — malware analysis report

Static analysis result for SHA-256 900a73dd5ad16a7c…

MALICIOUS

PDF

34.0 KB Created: 2021-07-06 02:57:55 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 545016f82d5df3d43c329f077e71c5a7 SHA-1: 49526dfe0bc1de437a38eadf8db64d9078dff244 SHA-256: 900a73dd5ad16a7c978229c56313aaba9cd499162f7d3fecc70a37a94fa7f730
220 Risk Score

Malware Insights

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

The PDF contains a malicious link disguised as a game hack or free generator, which redirects to known malicious infrastructure. The document also displays a fake CAPTCHA to trick users into interacting with the malicious content. While no scripts were explicitly extracted, the malformed stream and ML classifier suggest exploitation is likely occurring.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://netcdn.tw/app/431946152/rbx-claim-game-hack In PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/coin-master-hacks-for-free-spins_GM406889139.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/robux-redeem-code-hack_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/latest-coin-master-free-spins-link_GM406889139.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/games-that-give-free-robux_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/minecraft-pe-free-download-android_GM479516143.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/free-roblox-redeem-codes-that-havent-been-used_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/coin-master-guide-to-free-spins-and-rewards_GM406889139.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/mc-hacks_GM479516143.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/how-to-get-stuff-that-cost-coins-free-mcpe-master_GM406889139.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/coin-master-free-spins-link-today-blogspot_GM406889139.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/roblox-piano-hack-2021_GM431946152.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/non-download-roblox-hack_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/minecraft-pe-015-0-apk-free-download_GM479516143.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/roblox-rise-of-nations-hack_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/spin-free-coin-master_GM406889139.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/how-to-get-free-robux-easy-2021_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/free-roblox-injector_GM431946152.pdfIn PDF document text
    • http://www.elibrary.fl.unud.ac.id/repository/how-to-hack-into-peoples-account-in-roblox_GM431946152.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/free-spin-generator-for-coin-master_GM406889139.pdfIn PDF document text
    • http://elibrary.fl.unud.ac.id/repository/free-robux-generator-roblox-no-survey-pc_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
font_00_sfnt_off00003049.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3049 22408 bytes
SHA-256: bdbaad2ac2f3a22282b5b3aa6c988eeea76b2e16f1bea56ef879b423164dc84e
font_01_sfnt_off000060d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x60D5 18724 bytes
SHA-256: 94011f647025b503e1bd5fbae3f7f94a970aab3ad666f12f92045861b57b65bb

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