Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb9a16c61ceca087…

MALICIOUS

PDF

68.7 KB Created: 2021-09-28 18:15:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a95e523eb37ccb7203da2279fd840ab7 SHA-1: 575f9a346fef2bcf5ba91a3a0f7759ba1a881d77 SHA-256: cb9a16c61ceca087d592b3fe70ebae9da8f6e3bf130d7d31e7ab971ab252d515
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 or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://pistant.ru/uplcv?utm_term=top+moba+games+for+android PDF link annotation
    • https://areopag.ru/sites/default/files/uploads/23259499463.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/kosuwalabare.pdfIn PDF document text
    • https://biomedchita.ru/imeg_master/file/91637314921.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/devodiwumore.pdfIn PDF document text
    • http://currycornersugarland.com/admin/images/file/52809655172.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/2016906081.pdfIn PDF document text
    • https://olympicwroclaw.pl/zdjecia/fck/file/28108522603.pdfIn PDF document text
    • http://thietbinuoitom.vn/uploads/userfiles/file/57170599139.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613057e02db3f---64995207454.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/fe1d28ca13885da582f3dadd5b99eda9/47614935157.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210901_F1F59A44C35806BB.pdfIn PDF document text
    • http://www.udelimpa.es/ckfinder/userfiles/files/27041291956.pdfIn PDF document text
    • http://ecosdaliberdade.com/ckfinder/userfiles/files/sigogoledumabu.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/79827714906.pdfIn PDF document text
    • http://budget-pl.com/ckfinder/userfiles/files/89011952305.pdfIn PDF document text
    • http://topoint.cc/userfiles/fckFile/20210918035350.pdfIn PDF document text
    • https://zd-zeta.com/uploads/files/202109090110193765.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/7af30cccf507acd0852aef88d3eaca11/zuvegefup.pdfIn PDF document text
    • http://vln.nl/files/file/xefejevopaximegomamajiga.pdfIn PDF document text
    • http://kanizsakran.hu/userfiles/file/61251164768.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000abbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xABBD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c3cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3CF 16336 bytes
SHA-256: a63cebebcf5c4de43c89dbea5eba50be40f7ab74b2f5b96758955f783b8ad6e4
font_02_sfnt_off0000ed32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED32 10800 bytes
SHA-256: 5821b37137960c686499cad01c688c05db8f9445670c1023fd5ff1a157ac95bf