Malicious PDF — malware analysis report

Static analysis result for SHA-256 881cbc358c92ea85…

MALICIOUS

PDF

47.6 KB Created: 2021-05-14 06:25:42 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 1918b4b1f76e155a3ba6e1481e0ebc2c SHA-1: 3d4d5fb0906e2f92e74d80668d2b19fc2c46be05 SHA-256: 881cbc358c92ea85214075c823fe37ac6ab9f6d128c0419a76b39e037b1edc10
142 Risk Score

Malware Insights

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

The PDF document contains a fake CAPTCHA lure, aiming to trick the user into interacting with a link. The document also contains a large number of external links, suggesting a link farm or SEO poisoning attempt. The primary URL, https://netcdn.xyz/app/431946152/free-roblox-outfits-game-hack, is likely the destination for a malicious payload download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9013

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/free-roblox-outfits-game-hack
    • http://www.vktzunami.cz/images/best-free-minecraft-server-hosting_GM479516143.pdf
    • http://www.vktzunami.cz/images/coin-master-free-spins-ios-app_GM406889139.pdf
    • http://www.vktzunami.cz/images/free-spins-and-coins-on-coin-master_GM406889139.pdf
    • http://www.vktzunami.cz/images/cpbildco-robux_GM431946152.pdf
    • http://www.vktzunami.cz/images/coin-master-free-coins-and-spins_GM406889139.pdf
    • http://www.vktzunami.cz/images/coin-master-daily-free-spins-link-app-download_GM406889139.pdf
    • http://www.vktzunami.cz/images/how-to-hack-roblox-to-get-robux_GM431946152.pdf
    • http://www.vktzunami.cz/images/free-spins-coin-master_GM406889139.pdf
    • http://www.vktzunami.cz/images/coin-master-free-stars_GM406889139.pdf
    • http://www.vktzunami.cz/images/free-spins-for-coin-master_GM406889139.pdf
    • http://www.vktzunami.cz/images/free-robux-no-verification-needed_GM431946152.pdf
    • http://www.vktzunami.cz/images/coin-master-daily-free-spins-link-today_GM406889139.pdf
    • http://www.vktzunami.cz/images/coin-master-free-spins-twitter_GM406889139.pdf
    • http://www.vktzunami.cz/images/www-coin-master-hack-com_GM406889139.pdf
    • http://www.vktzunami.cz/images/minecraft-hacker-skin_GM479516143.pdf
    • http://www.vktzunami.cz/images/free-coin-master-spins-daily_GM406889139.pdf
    • http://www.vktzunami.cz/images/coin-master-100-spin_GM406889139.pdf
    • http://www.vktzunami.cz/images/coin-master-daily-free-spins-link-today-haktuts_GM406889139.pdf
    • http://www.vktzunami.cz/images/how-to-get-minecraft-for-free-on-mobile_GM479516143.pdf
    • http://www.vktzunami.cz/images/free-multiplayer-minecraft-server_GM479516143.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off00004bfc.bin
657b56ae714b477785d316f37b6f66a7dc795336a4515675409746b6baaca67f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4BFC 26932 bytes
font_01_sfnt_off00008a95.bin
450e3ee45915afe13702bf1d587eb8b9ad88a8d2113419ac9f2fd116a828e139
pdf-font-stream PDF embedded font (sfnt) at offset 0x8A95 5696 bytes
font_02_sfnt_off000097a7.bin
90da43312d6bb992ca5b038b2bc6e2b12c2c9d98bca064d3c60a0cee32c74c59
pdf-font-stream PDF embedded font (sfnt) at offset 0x97A7 18312 bytes