Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ef06d5b8f291952…

MALICIOUS

PDF

44.6 KB Created: 2021-06-08 10:02:16 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: edc81d471e27ee234ff324fc90c43199 SHA-1: a71cca3af6e49f45fd9693f921385de5a1b63512 SHA-256: 6ef06d5b8f2919529fb40272e1c5adf58767797f31c5b08cd2c06bf806ee4c93
102 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are structured as SEO-friendly URLs pointing to game-related content, suggesting a link farm or phishing lure. The ML classifier also flagged this PDF as malicious with high confidence. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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-download-roblox-dino-simulator-hack-game-hack
    • http://achauco.vn/public/upload/files/info-roblox-com-robux_GM431946152.pdf
    • http://achauco.vn/public/upload/files/how-to-get-minecraft-for-free-on-mobile_GM479516143.pdf
    • http://achauco.vn/public/upload/files/free-foxy-food-coin-master_GM406889139.pdf
    • http://achauco.vn/public/upload/files/coin-master-levels_GM406889139.pdf
    • http://achauco.vn/public/upload/files/roblox-promo-codes-free-robux_GM431946152.pdf
    • http://achauco.vn/public/upload/files/cute-free-hair-on-roblox_GM431946152.pdf
    • http://achauco.vn/public/upload/files/free-robux-redeem-codes_GM431946152.pdf
    • http://achauco.vn/public/upload/files/coin-master-free-spins-link-2021-today_GM406889139.pdf
    • http://achauco.vn/public/upload/files/how-to-hack-roblox-games_GM431946152.pdf
    • http://achauco.vn/public/upload/files/coin-master-free-spins-haktuts_GM406889139.pdf
    • http://achauco.vn/public/upload/files/roblox-cp_GM431946152.pdf
    • http://achauco.vn/public/upload/files/mcpe-com_GM479516143.pdf
    • http://achauco.vn/public/upload/files/free-spin-and-coin-blogspot_GM406889139.pdf
    • http://achauco.vn/public/upload/files/how-do-you-get-free-roblox_GM431946152.pdf
    • http://achauco.vn/public/upload/files/freecoins_GM406889139.pdf
    • http://achauco.vn/public/upload/files/free-tiktok-likes-and-views_GM835599320.pdf
    • http://achauco.vn/public/upload/files/hey-google-how-do-you-get-free-robux_GM431946152.pdf
    • http://achauco.vn/public/upload/files/how-to-get-free-coins-in-coin-master_GM406889139.pdf
    • http://achauco.vn/public/upload/files/how-to-free-robux_GM431946152.pdf
    • http://achauco.vn/public/upload/files/free-coins-and-spins-in-coin-master_GM406889139.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00004f53.bin
f7108b87dafe2b4caa879173037a47d24ec0e3d8b914a27f924bccf07c0693ea
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4F53 25636 bytes
font_01_sfnt_off00008882.bin
011b9a1bc6a339c925f4e12d93326b740cbf7a70a980012b63caae9e5dd4329f
pdf-font-stream PDF embedded font (sfnt) at offset 0x8882 19312 bytes