Malicious PDF — malware analysis report

Static analysis result for SHA-256 a017f8963b9f11e0…

MALICIOUS

PDF

79.2 KB Created: 2021-09-06 13:50:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ceb40e1de4c6cd0c712f31062aa41df6 SHA-1: 04b5984569370e2698566e3ea86d9b442f20042b SHA-256: a017f8963b9f11e08c5d20e26eb0062d42245a43d9b7c858714eec7085457be4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to a link farm strategy, likely intended to redirect users to phishing or malware-hosting sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not meant for direct user consumption but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://queure.ru/uplcv?utm_term=beauty+and+the+beast+belle+piano+sheet+music+pdf PDF link annotation
    • http://seoulgreeter.com/userData/board/file/39565324564.pdfIn PDF document text
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/b1678e76fb7b9eb7f0014dca3847bb06/vaxapijopovumajober.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f19c92071d---79877970844.pdfIn PDF document text
    • http://charivne.info/images/file/kojixonuzejiwusuji.pdfIn PDF document text
    • http://therealmccoyfamilyreunion.com/clients/f/f9/f9ea119420dddc0cc5ac7622830b9f68/File/wisovuzenelevixogel.pdfIn PDF document text
    • https://hirurgija.me//files/47220232128.pdfIn PDF document text
    • http://cocoal.com/uploads/file/35930117116.pdfIn PDF document text
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/d3fe06feb7bbbee64feebcc90d9ff3b6/55038271409.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc469e85ad---38434419714.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/91239676090.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/89771139000.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a351449bb96---70489222760.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ad119e525de---15249066372.pdfIn PDF document text
    • https://drisraadentalcenter.com/userfiles/file/31810445926.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/6b875a97f9308c70a2182123ea8b065f/22612668839.pdfIn PDF document text
    • http://ecompletecontact.com/ckfinder/userfiles/files/54685403362.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/tixezolap.pdfIn PDF document text
    • http://starrsgazette.com/admin/images/file/zikemo.pdfIn PDF document text
    • http://semihkerpiccilervesupersound.com/upload/file/93739709332.pdfIn PDF document text
    • http://123podkrovie.sk/editor_uploads/files/zijamosebemubofodeja.pdfIn PDF document text
    • http://feynburg-uhren.de/uploads/38887929683.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/99353170627.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b424bb8c1e---luxuxubikexitapanazulotoj.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/16083e91699ca9---4028639465.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_off0000cec9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEC9 17680 bytes
SHA-256: 8442b0227d1fcabd4d0af5e8e3cef3fcd94f92bca55c55879cb7723dfe0667ce
font_01_sfnt_off0000fca5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114BC 11192 bytes
SHA-256: 305a7678d4a91ce8e9eda44d74dcada7e685ed7a0504002065a5fc2f64bd5382