Malicious PDF — malware analysis report

Static analysis result for SHA-256 94d171aea7127240…

MALICIOUS

PDF

46.8 KB Created: 2021-05-14 09:38:00 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: d412794e9262c8e0d36d90dc87cd86f5 SHA-1: bdfb1e41126af8e0f942d186fad24fa3c94481ab SHA-256: 94d171aea712724074bd3fd5ca081abd8bdb5e7e88b49bd6b9c06c821c8373e4
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a fake CAPTCHA lure and a large number of external links, many of which point to other PDF files, suggesting a link farm designed to trick users into downloading potentially malicious content. The ML classifier also flagged this PDF as malicious with a high probability. No scripts were extracted, but the presence of numerous links and the fake CAPTCHA heuristic strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8948

Heuristics 5

  • 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.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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/431946152/www-robux-redeem-game-hack
    • http://umksn.pl/images/coin-master-deals_GM406889139.pdf
    • http://umksn.pl/images/free-vpn-for-minecraft_GM479516143.pdf
    • http://umksn.pl/images/coin-master-free-spins-and-coins-hack_GM406889139.pdf
    • http://umksn.pl/images/coin-master-free-spin-and-trading-group_GM406889139.pdf
    • http://umksn.pl/images/free-spin-in-coin-master_GM406889139.pdf
    • http://umksn.pl/images/blogger-coin-master-free-spins_GM406889139.pdf
    • http://umksn.pl/images/free-spins-coin-master-hack-2021_GM406889139.pdf
    • http://umksn.pl/images/robux-hack_GM431946152.pdf
    • http://umksn.pl/images/how-to-get-free-robux-instantly_GM431946152.pdf
    • http://umksn.pl/images/100-free-coin-master-spins_GM406889139.pdf
    • http://umksn.pl/images/minecraft-hacked-client-bedrock_GM479516143.pdf
    • http://umksn.pl/images/free-spins-for-coin-master-2021_GM406889139.pdf
    • http://umksn.pl/images/coin-master-daily-free-spins-link-today_GM406889139.pdf
    • http://umksn.pl/images/how-do-you-get-free-roblox_GM431946152.pdf
    • http://umksn.pl/images/how-to-get-roblox-premium-for-free_GM431946152.pdf
    • http://umksn.pl/images/free-shirt-roblox_GM431946152.pdf
    • http://umksn.pl/images/free-robux-codes_GM431946152.pdf
    • http://umksn.pl/images/free-spins-on-coin-master-generator_GM406889139.pdf
    • http://umksn.pl/images/codes-how-to-get-free-robux_GM431946152.pdf
    • http://umksn.pl/images/best-way-to-hack-coin-master_GM406889139.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off000046d5.bin
950b9e8ffc9abcdae7ce68aa117a41cc2d2ed43204533270a4f9308fdd0bfa19
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x46D5 26828 bytes
font_01_sfnt_off00008629.bin
450e3ee45915afe13702bf1d587eb8b9ad88a8d2113419ac9f2fd116a828e139
pdf-font-stream PDF embedded font (sfnt) at offset 0x8629 5696 bytes
font_02_sfnt_off0000933b.bin
61e1175fd0613718da88e3f59775346477bef0226bc79823f694c1fc9380e365
pdf-font-stream PDF embedded font (sfnt) at offset 0x933B 18648 bytes