Malicious PDF — malware analysis report

Static analysis result for SHA-256 d317bb1e96c26158…

MALICIOUS

PDF

45.2 KB Created: 2021-06-03 09:28:27 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 1fc925a84bd0c52a37cdd12d2c3a6d18 SHA-1: 011527339bc3a654370d22a1ec027731144ac6ec SHA-256: d317bb1e96c26158fe278a52210fd3da1506d0d4551252dfeac5fa8b027eee5a
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are structured as SEO-optimized PDF links, suggesting a link farm. The document body and extracted URLs indicate a lure for free virtual currency or game hacks, likely directing users to malicious sites. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9864

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.online/app/431946152/free-robux-without-human-verification-game-hack
    • https://www.efeskbb.com/upload/content/files/free-spins-for-coin-master-game_GM406889139.pdf
    • https://www.efeskbb.com/upload/content/files/robux-hack-free-robux_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/games-that-give-you-free-robux_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/minecraft-free-trial_GM479516143.pdf
    • https://www.efeskbb.com/upload/content/files/free-robux-without-human-verification_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/best-way-to-get-free-robux_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/coin-master-hack-no-verification_GM406889139.pdf
    • https://www.efeskbb.com/upload/content/files/free-robux-today_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/coin-master-free-spin-facebook-link_GM406889139.pdf
    • https://www.efeskbb.com/upload/content/files/minecraft-free-apk-java-edition_GM479516143.pdf
    • https://www.efeskbb.com/upload/content/files/free-robux-no-human-verification-and-no-survey_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/free-roblox-cards-pin-number_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/how-to-get-minecraft-windows-10-for-free_GM479516143.pdf
    • https://www.efeskbb.com/upload/content/files/coin-master-gold-cards-free_GM406889139.pdf
    • https://www.efeskbb.com/upload/content/files/roblox-fun-com-free-robux_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/robux-free-gift-card-org-hack_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/avatar-de-roblox_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/coin-master-free-spin-ml_GM406889139.pdf
    • https://www.efeskbb.com/upload/content/files/roblox-hack-com_GM431946152.pdf
    • https://www.efeskbb.com/upload/content/files/reddit-coin-master-hack_GM406889139.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00005218.bin
4a24b08020609b882fd2b09faebdc76da157c19db19ed9d34624ea39e9b02fa8
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5218 24932 bytes
font_01_sfnt_off00008b88.bin
69162c0303826e3a88150cee7b6b12b50ba56e04bc46253c0e5eb9f80ac8a399
pdf-font-stream PDF embedded font (sfnt) at offset 0x8B88 19224 bytes