Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfa58dfe534798d1…

MALICIOUS

PDF

35.8 KB Created: 2021-07-02 06:36:45 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-15
MD5: bfff807a91f63131564a3c90eb9901f1 SHA-1: 91b6519d43ee1d17fa7c1b3612779b26b82a7457 SHA-256: cfa58dfe534798d159a1d8949d453b22ec8cd1479f1dbf6743867921ca59c986
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous external links, many of which are SEO-optimized and point to other PDF files, suggesting a link farm designed to attract users searching for game cheats or hacks. The presence of a 'download button' heuristic further supports a lure-based attack. The ML classifier strongly flagged this PDF as malicious, indicating a high likelihood of malicious intent, likely to download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://netcdn.co/app/431946152/roblox-play-as-guest-free-no-download-game-hack PDF link annotation
    • https://www.mentalhealthnow.co.uk/uploads/files/files/roblox-hack-confirm-passord_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/minecraft-free-apk-java-edition_GM479516143.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-coin-master-spins-and-coins_GM406889139.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-robux-that-actually-works-2021_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/minecraft-xbox-one-free_GM479516143.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-roblox-money_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/beta-this-obby-to-get-free-robux_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/play-minecraft-free-online-no-download_GM479516143.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/how-are-people-able-to-cheat-in-items-in-roblox_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/rexic-roblox-hack-full-lua_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/roblox-games-with-free-vip-servers_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-coin-master-spins-2021_GM406889139.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/google-how-do-you-get-free-robux_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/op-rewards-free-robux_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-robux-group-funds-website_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/coin-master-free-spins-facebook_GM406889139.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/how-to-earn-free-robux_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/how-to-get-free-robux-in-iphone_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-barbie-roblox-games_GM431946152.pdfIn PDF document text
    • https://www.mentalhealthnow.co.uk/uploads/files/files/free-synapse-roblox_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_off00003104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3104 23072 bytes
SHA-256: d61237ce95522a5417fa47e203c9574f1303485b50bfbb887410f1db08dae4d8
font_01_sfnt_off000064d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x64D6 19732 bytes
SHA-256: 724256d6c934b81ac4fca496f002a1f6bc91f4ee4ccca99bb0db8ab84e0b16dd