Malicious PDF — malware analysis report

Static analysis result for SHA-256 e2528c6ecacad3b6…

MALICIOUS

PDF

74.0 KB Created: 2021-04-28 13:47:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 8a6f143ec3388981b4a9ddaa2ee00202 SHA-1: 0c1f574edb991b538f8b2b88fa4d7e2e28c5a618 SHA-256: e2528c6ecacad3b6c67d76df9b6c58251eba668354cf4033d32be75597e6cf25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF document detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and 'Qt', indicating it was likely generated by a tool rather than being a legitimate document. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the malicious intent of directing users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d511b3247a---64498221352.pdf In PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/b08a65b9d6c822d9e2cead0522f34b42/15203263624.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/ee81c46d23ce714e1419c3864b014e36/niwezisigipubolo.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/c3429eb612405f12febe78310b502dd5/27054944130.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/hp236g45cn3i7qc0i025l3a4j1/87056337300.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16087c3e763eb7---89612846181.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160813fbd6518d---46230260116.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/ec05433a630baf0e74862e4b9033ef4c/zeviloxemijisapitaregije.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/e16c1529cd43006b053ad4609a1b014f/18810494290.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/76398337912.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/n40pdasg4jqv66pvcgi8m14dka/waxupobajatefoligujuf.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089397628196---69622211708.pdfIn PDF document text
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160720e5e9ed31---32540786516.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16085264672a0a---55135634743.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/20nvcjevnkv1bgkdaqqhm35pd2/domanokorekowo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=dota+2+heroes+lane+guidePDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e484.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE484 5220 bytes
SHA-256: be036ed80a6772d9fd900a037c68265155895fb96bd591c82941065734cf2207
font_01_sfnt_off0000f643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF643 10536 bytes
SHA-256: 77da3eebb6d3cbe4df48fdaddcbb94a34291667930eb30a997b5d719d1e63800