Malicious PDF — malware analysis report

Static analysis result for SHA-256 f398fcc63a91979f…

MALICIOUS

PDF

42.6 KB Created: 2021-05-19 20:37:45 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: a3b687bf8add495c7e760499f852c479 SHA-1: 1e0dc4d28859d2352b199ad4aa7fde1381d6cb73 SHA-256: f398fcc63a91979f116c78b41a4c68eed4be9f533e1563d604f9d52ed858fe9e
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 SEO-optimized and point to other PDF files, suggesting a link farm or content distribution network for malicious files. The presence of a 'download button' heuristic further supports the idea that the document is designed to trick users into downloading further content. The ML classifier strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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.xyz/app/835599320/tiktok-free-britney-game-hack
    • https://luyenthitoanpro.com/public/upload/files/coin-master-twitter-free-spins_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/spin-links-for-coin-master_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/actual-free-robux_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/hack-the-coin-master-game_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/free-robux-with-no-human-verification_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/my-robux_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/minecraft-hax-download-no-virus_GM479516143.pdf
    • https://luyenthitoanpro.com/public/upload/files/coin-master-free-mighty-lion-card_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/cool-minecraft-hacks_GM479516143.pdf
    • https://luyenthitoanpro.com/public/upload/files/wurst-commands_GM479516143.pdf
    • https://luyenthitoanpro.com/public/upload/files/free-bling-bling-card-coin-master_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/minecraft-games-to-play-for-free_GM479516143.pdf
    • https://luyenthitoanpro.com/public/upload/files/free-robux-without-human-verification-real_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/how-to-earn-robux-for-free-2021_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/www-roblox-com-robux-free_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/free-robux-generator-without-verification_GM431946152.pdf
    • https://luyenthitoanpro.com/public/upload/files/minecraft-free-apk-java-edition_GM479516143.pdf
    • https://luyenthitoanpro.com/public/upload/files/free-spins-coin-master-no-verification_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/coin-master-hack-app-ios_GM406889139.pdf
    • https://luyenthitoanpro.com/public/upload/files/how-to-get-free-robux-without-surveys_GM431946152.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off00004987.bin
d62542ba74797d0052827a071ca2975bee2355387fe9d6e770c3eebd3cd11b2a
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4987 26272 bytes
font_01_sfnt_off0000859f.bin
8794fc8cc6d59f8b7bf2a1beba7f0e75f1a85dee05061da5c2fad573c1b24f90
pdf-font-stream PDF embedded font (sfnt) at offset 0x859F 17852 bytes