Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1af63da91172547…

MALICIOUS

PDF

91.4 KB Created: 2021-09-19 09:07:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e4e7e8bb21621101b6fb3f47977bef5 SHA-1: d52b0c1fa76e9fe09e2a8a84f4dc9ea7f8656642 SHA-256: a1af63da91172547e48cc339e25370f9a04b0923c9d63bbbd0a83e6c1c7a85f8
114 Risk Score

Malware Insights

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

The PDF document employs a fake CAPTCHA lure to deceive users into downloading further content. The presence of numerous external URLs, many with 'utm_term' parameters suggesting tracking, indicates a link farm designed to distribute malicious files. The ML classifier strongly flagged this PDF as malicious, supporting the observed attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9906

Heuristics 6

  • 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
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://huntic.ru/uplcv?utm_term=nba+2k20+obb+free+download+for+android
    • https://digireg.li/upload/gufagenuvemapelegom.pdf
    • https://k-barrierfree.com/FileData/ckfinder/files/20210908_0F5A397EB4BA6E47.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130582b36036---1338920870.pdf
    • https://esz.jp/img/editor/files/65595833342.pdf
    • https://eravukappalpalli.com/userfiles/file/3085373319.pdf
    • https://www.milestonesmn.org/ckfinder/userfiles/files/fenopafudilek.pdf
    • http://smalternatywa.pl/media/upload/files/f9b1e116b2b6a631cbd205feff431495.pdf
    • https://swiz.eu/files/editor/divedinakonizuvubefabab.pdf
    • http://dorrstrechy.cz/UserFiles/File/lorivape.pdf
    • http://investbuild.ru/var/upload/file/guparobavenibutevuro.pdf
    • http://www.gobarging.com/uploads/textareas/file/nesitebuw.pdf
    • http://dragonspond.com/uploads/files/bidetenojaxiw.pdf
    • http://weighlessthisyear.com/ckfinder/userfiles/files/14281178567.pdf
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/4e1694e3ed85f40d337cec26d8646889/27770512440.pdf
    • http://lrpharmaceutical.com/upload/files/ronezeviranokibesi.pdf
    • https://uleiuri.ro/userfiles/file/nofivigunid.pdf
    • http://bbhshipyard.com/userfiles/file/pizanetupakak.pdf
    • https://mclandpin.com/calisma2/files/uploads/powuxeto.pdf
    • http://location-appartement-venise.com/italie_documents/files/20360510406.pdf
    • http://mnarch.it/userfiles/files/nupabetoxani.pdf
    • https://samajsutra.com/userfiles/files/denibisip.pdf
    • http://mkconline.com/landmark/ckfinder/userfiles/files/5157228853.pdf
    • http://merrygoldholidays.com/ckfinder/userfiles/files/sevajusuxelewowusaxapipul.pdf
    • https://burkina-businessschool.com/business_school/uploads/file/40785611841.pdf
    • http://nebovsem.ru/app/webroot/files/files/wevujunesoxaxovefi.pdf
    • https://hainutedecopii.eu/ckfinder/userfiles/files/lakogesimemamodor.pdf
    • http://elitacasa.it/images/file/tuzavaragakuroxu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fc0f.bin
bbccc3731d5926f2fa8b7649ffe35046145d0463d442e748c0436f36a1c79efc		 pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0F 19504 bytes
font_01_sfnt_off00012f2a.bin
34825ee98adc18b6bb7f32074aa1d95282ea9cd946c9c72a6815552abd95705d		 pdf-font-stream PDF embedded font (sfnt) at offset 0x12F2A 10616 bytes
font_02_sfnt_off000147a1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0x147A1 16792 bytes

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