Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8a35cc698234084…

MALICIOUS

PDF

47.5 KB Created: 2021-06-07 16:12:41 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 0ecc8a6050da9d6890addf94646d7ca6 SHA-1: c0c925e9d3751ffff9a7b0bf709d1a7355a17214 SHA-256: b8a35cc6982340843726b42a14772390a2ab9015784c807108c09ef83912b8b0
182 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. It uses brand-impersonation credential phishing. The file embeds a large number of external links characteristic of an SEO link farm, routes users through malicious redirector infrastructure and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9769

Heuristics 6

  • 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.
  • PDF links to a 'free generator / game hack' redirector high PDF_GAME_HACK_REDIRECT_LURE
    PDF's clickable action targets a redirector of the form /app/<id>/<slug>-game-hack — the landing-page shape of a large SEO 'free spins / generator / game hack' lure family that funnels victims through rotating disposable hosts to a malware/scam payload. The multi-link variants also trip ML/link-farm rules; this catches the single-link variants that otherwise score clean.
  • Brand-impersonation credential phishing lure high SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: call-to-action link host does not match the impersonated brand: https://netcdn.tw/app/431946152/www-roblox-com-free-account-game-hack.
  • 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.tw/app/431946152/www-roblox-com-free-account-game-hack PDF link annotation
    • http://mou16-murmansk.ru/images/coin-master-free-coins-hack_GM406889139.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-get-free-roblox-money_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/free-robux-no-verification-2021-ios_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/earnrobux_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-get-free-robux-on-roblox-2021_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/free-minecraft-bedrock-server_GM479516143.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-get-roblox-premium-for-free-2021_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/minecraft-java-edition-download-free_GM479516143.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/free-roblox-adopt-me-pets_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-get-free-spins-in-coin-master_GM406889139.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-hack-into-someones-roblox-account_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/coin-master-coins-free_GM406889139.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/free-minecraft-capes_GM479516143.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-change-roblox-username-for-free_GM431946152.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-get-free-chest-in-coin-master_GM406889139.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/coin-master-gold-cards-free-2021_GM406889139.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/best-minecraft-hacked-client-2021_GM479516143.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/coin-master-free-spin-and-coins-links_GM406889139.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/minecraft-tiktok-hacks_GM479516143.pdfIn PDF document text
    • http://mou16-murmansk.ru/images/how-to-host-a-minecraft-server-for-free_GM479516143.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00004ef4.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4EF4 26744 bytes
SHA-256: 89482687208309d12d37aa6ff491771574a80ecfb683c22cf3710f424b65aaad
font_01_sfnt_off00008b67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8B67 2824 bytes
SHA-256: 94c1b019735d7e491765340abe50b2897410e2ec65ecf141c08bd9f2220897c4
font_02_sfnt_off00009516.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9516 18816 bytes
SHA-256: 10c9e7bd2dc33bcba5e9fb53d579e104c06ad6cd20807ae238c6cea047c56e75

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