Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd4b9af5756e5c51…

MALICIOUS

PDF

36.2 KB Created: 2021-07-06 15:05:21 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: b4929c9c28bd6c1144cbccf724545608 SHA-1: 1e22725278ced36bc96dd9b5ff282962b9869bb8 SHA-256: cd4b9af5756e5c51073cb7ad6823bb293dee1e6cf5331b981ba1defc685e60bc
102 Risk Score

Malware Insights

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

The PDF document contains numerous links to external websites, many of which are presented as guides or hacks for obtaining free in-game currency for popular games like Roblox and Coin Master. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of such links, suggesting a coordinated effort to direct users to potentially malicious sites. The ML classifier also strongly flagged this PDF as malicious, reinforcing the suspicious nature of the content.

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.tw/app/431946152/how-to-get-free-robux-without-downloading-apps-2021-game-hack
    • https://cleansui.com.tw/image/data/files/free-robux-no-buying-things_GM431946152.pdf
    • http://cleansui.com.tw/image/data/files/microsoft-rewards-robux_GM431946152.pdf
    • http://cleansui.com.tw/image/data/files/how-to-get-minecraft-java-free_GM479516143.pdf
    • https://cleansui.com.tw/image/data/files/hack-roblox-games-app_GM431946152.pdf
    • http://cleansui.com.tw/image/data/files/how-to-get-robux-for-free-2021_GM431946152.pdf
    • https://cleansui.com.tw/image/data/files/how-to-get-free-robux-easy-hack_GM431946152.pdf
    • http://cleansui.com.tw/image/data/files/free-coin-master-spins-link-download_GM406889139.pdf
    • http://cleansui.com.tw/image/data/files/free-spins-for-coin-master-game_GM406889139.pdf
    • https://cleansui.com.tw/image/data/files/how-to-get-free-robux-easy-no-download_GM431946152.pdf
    • http://cleansui.com.tw/image/data/files/roblox-games-that-will-give-you-free-robux_GM431946152.pdf
    • https://cleansui.com.tw/image/data/files/moonactive-coin-master-free-spins_GM406889139.pdf
    • https://cleansui.com.tw/image/data/files/blogspot-free-spins-coin-master_GM406889139.pdf
    • https://cleansui.com.tw/image/data/files/coin-master-hack-spin-generator-tool_GM406889139.pdf
    • https://cleansui.com.tw/image/data/files/coin-master-free-spin-app-2021_GM406889139.pdf
    • https://cleansui.com.tw/image/data/files/how-to-play-roblox-for-free_GM431946152.pdf
    • https://cleansui.com.tw/image/data/files/roblox-robux-hack-generator_GM431946152.pdf
    • https://cleansui.com.tw/image/data/files/pokemon-go-free-and-apple-watch_GM1094591345.pdf
    • https://cleansui.com.tw/image/data/files/roblox-admin-hack-cheat-engine_GM431946152.pdf
    • https://cleansui.com.tw/image/data/files/ninja-legends-hackauto-farmer-free-op-swordroblox_GM431946152.pdf
    • https://cleansui.com.tw/image/data/files/cheat-engine-64-roblox-speed-hack_GM431946152.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000032dd.bin
0ea3876f994a28ec1ff793e77bc58c918e08873054f31da8075b1a6ff94092fc
pdf-font-stream PDF embedded font (sfnt) at offset 0x32DD 22260 bytes
font_01_sfnt_off00006442.bin
bbee3cd2d045934f3587faaae269c5438879465e49c598d076b35cc198d7b491
pdf-font-stream PDF embedded font (sfnt) at offset 0x6442 20464 bytes