Malicious PDF — malware analysis report

Static analysis result for SHA-256 6fce391691d5f290…

MALICIOUS

PDF

44.1 KB Created: 2021-05-13 06:01:08 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 531280caf9c02c1aa8089810646523d9 SHA-1: 69f150f94f26ca83b68484e8ef9831920fda274e SHA-256: 6fce391691d5f290b3467ce2ae2abd75dc7e7a90073aad6e9743efee7acb31e7
200 Risk Score

Malware Insights

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

The PDF document contains a lure for a "free generator" and displays a fake CAPTCHA to trick users into interacting with malicious links. The embedded URL `https://netcdn.xyz/app/406889139/free-pet-food-for-coin-master-game-hack` is identified as a known malicious redirector. The document body also contains numerous links to other PDF files hosted on `achauco.vn`, suggesting a potential chain of malicious downloads or redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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.
  • 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
  • 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.xyz/app/406889139/free-pet-food-for-coin-master-game-hack In PDF document text
    • http://achauco.vn/public/upload/files/coin-master-free-coins-and-spins-2021_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-roblox-groups-with-funds_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/minecraft-bedrock-edition-pc-free_GM479516143.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/earn-free-robux-for-roblox_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-daily-spins-coin-master-2021_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-online-spins-coin-master_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/how-to-get-free-pet-food-in-coin-master_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/minecraft-bedrock-client_GM479516143.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/can-i-hack-coin-master-with-lucky-patcher_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-robux-thumbnail_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/robux-games_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/robux-converter_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/daily-free-spins-coin-master-2021_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/coin-master-hack-review_GM406889139.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-robux-pins_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/get-free-robux-no-human-verification_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/robux-xyz_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/robux-free-c_GM431946152.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/minecraft-hacked-client-download_GM479516143.pdfIn PDF document text
    • http://achauco.vn/public/upload/files/free-robux-promo-codes-2021_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_003_off00004b43.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4B43 29816 bytes
SHA-256: 2d3a6275f821398f6fff21875db68d16e8f6e6978a59994e4fd7210a1f7780c8
font_01_sfnt_off00008aca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8ACA 18040 bytes
SHA-256: 80b08f0f47efeae7474973f213c4bda075b9244837f94a62dadeca22caed91d8