Malicious PDF — malware analysis report

Static analysis result for SHA-256 3586c6648faafd69…

MALICIOUS

PDF

80.7 KB Created: 2021-08-04 06:08:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: af5e943a8c4f6aa81dee55c8420a4a07 SHA-1: 032b69b26cf2d96693c0372ba50a3ed14aae5d56 SHA-256: 3586c6648faafd6998f25ed928915b8a4c2f4e444e5a901b0d0e1db7e80b8b73
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the presence of external URIs and the nature of the heuristics point towards a malicious PDF designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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=comptia+linux%2B+study+guide+exam+xk0-004+pdf+download
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8f531f80d---98115491643.pdf
    • http://hum-lucknow.org/test/fckeditor/file/munilede.pdf
    • http://mexvp.com/ckfinder/userfiles/files/toxoraj.pdf
    • http://avandcie-automation.com/ckfinder/userfiles/files/93252689497.pdf
    • http://gibisch.org/files/files/poguwakisisove.pdf
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/vinoa05qnr3367m56apulad157/jikililarevez.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16106e49d136c8---29608607373.pdf
    • http://tochalco.com/uploads/files/bosumegaxasaxotikag.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607ead3459cfa---87090425400.pdf
    • https://pharmnet.cz/ckfiles/files/files/5889713832.pdf
    • https://mldom.xyz/web/img/podborky/files/jalot.pdf
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160764abbdc082---vejojugubefiton.pdf
    • http://instant-image.net/UserFiles/Site/File/93599163663.pdf
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/8a1947b60edb0b4ac62ada1e6df92791/folopo.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac8aae6139---92618828536.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160d8d6e9f08de---kafotevijogozawevonagefi.pdf
    • https://cooperspick.com/files/jijof.pdf
    • http://0-50.ru/userfiles/file/66432355337.pdf
    • http://www.sport-konyv.hu/userfiles/file/37420340574.pdf
    • http://roocenter.ru/upload/file/wamirurusezirisalitalove.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/mevanuvoba.pdf
    • http://geyikkimya.com/userfiles/upload/file/25973395992.pdf
    • http://cupta.org/userfiles/files/20210724073451.pdf
    • http://hurtmar.pl/Upload/file/wemuwopezinod.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_off0000d547.bin
cb6d9ab9008f49ef616528efe3a274ca03e2f099869160dd6bbecbd731afcd8c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD547 16776 bytes
font_01_sfnt_off00010122.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10122 16792 bytes
font_02_sfnt_off00011939.bin
46857424e6ad99f2d6d53be4ee67a3d6cc4efd262d4d615f0757024bb9358032
pdf-font-stream PDF embedded font (sfnt) at offset 0x11939 11500 bytes