Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4d7088f9617a77c…

MALICIOUS

PDF

35.4 KB Created: 2021-06-18 00:44:55 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-29
MD5: f3c131c450622954876a46d24e05a340 SHA-1: ea294e3372b9a8be7adae6995da2301423a2969e SHA-256: c4d7088f9617a77cf5bc96f7f21ac8e9e41a1778bc715a64791130df07b0279c
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, including one to 'netcdn.co' and many hosted on 'cosmosocean.com.tw', all masquerading as game hacks or generators. The ML classifier strongly indicates maliciousness, and the presence of external links suggests a phishing or malware distribution attempt. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a lure to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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.
  • 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.
  • 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.co/app/431946152/free-robux-hack-uk-game-hack PDF link annotation
    • https://cosmosocean.com.tw/upload/files/spins-coin-master_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/coin-master-free-spins--spins_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/free-robux-generator-no-human-verification_GM431946152.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/how-to-get-unlimited-robux_GM431946152.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/how-to-get-a-free-remote-raid-pass_GM1094591345.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/coin-master-free-spins-android_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/coin-master-free-spin-and-coins-links_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/minecraft-pe-apk-free-download_GM479516143.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/coin-master-mod_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/coin-master-free-spins-link-2021-today_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/roblox-mad-city-season-4-hack_GM431946152.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/free-robux-card-codes_GM431946152.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/free-coin-and-spin-for-coin-master_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/ultimate-free-spins-coin-master_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/www-cheatsk-com-coin-master-hack_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/get-free-spins-coin-master-2021_GM406889139.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/minecraft-pe-free_GM479516143.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/how-to-get-free-avatar-items-in-roblox_GM431946152.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/roblox-games-free_GM431946152.pdfIn PDF document text
    • https://cosmosocean.com.tw/upload/files/roblox-games-for-free-online-no-download-no-account_GM431946152.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00003243.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3243 23032 bytes
SHA-256: d9064e6b203d634cf5fa4fb425f39d8b892a67d7920f3ef6319e95cd9eb2f8c9
font_01_sfnt_off000065f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x65F7 18884 bytes
SHA-256: 8b5f15ab99a2e506743ccd3a5a8f8e5d886de693bd4f7ab1889135594ba31025

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