Malicious PDF — malware analysis report

Static analysis result for SHA-256 26ff9561a2d9f824…

MALICIOUS

PDF

75.5 KB Created: 2021-07-01 22:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 3a50a29b33e8e403c9a2d127aefb0396 SHA-1: 2b91b058f795016850a61df2840c335a781acccf SHA-256: 26ff9561a2d9f82446bcd580bd03ed8d0c06d4c2873f71341a51c9f442e96fac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories. These links likely serve as a lure to download further malicious content or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6aa4825ac---82793989450.pdf In PDF document text
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/aacd0b776b6c4e7f52cd08fdd4c5fdf6/jufat.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c00bb267ae---jifamumegukebov.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2acd89557---77980832573.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608544b9b0d49---52990228366.pdfIn PDF document text
    • https://vieclamxaydung24h.com/upload/files/92757734827.pdfIn PDF document text
    • https://atasuorganiktarim.com/upload/ckfinder/files/22727236274.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608097f71f4e2---rukubu.pdfIn PDF document text
    • http://4grd.com/cmsimages/file/99341681618.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607959c12fef5---zuwipevirizedaguve.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160750a1d3f658---37228904424.pdfIn PDF document text
    • https://satuldelut.ro/ckfinder/userfiles/files/43594551922.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/acab8f653bc24a0df11abc4d83279a25/57461576092.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/29547602374.pdfIn PDF document text
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/093aqm5bvrouca63027ovnk2gq/2508260746.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/adb44400985f098eb06c1cfdaa3b1258/siwoxoz.pdfIn PDF document text
    • http://derma-dts.de/files/file/vabilegovexugowoxegavetux.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/9f2699e1804b65e5deca0a3e2933064e/12187400094.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082b6014adb4---gudopo.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16082ccb7329b1---wotevitolevonezok.pdfIn PDF document text
    • https://lesura.net/userfiles/file/42875985013.pdfIn PDF document text
    • http://stromzeleny.cz/file/72115961878.pdfIn PDF document text
    • http://domholidays.com/userfiles/file/zugugepes.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/77035487271.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=intrapleural+pressure+during+forced+expirationPDF 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://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_off0000c4b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dcc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC7 10948 bytes
SHA-256: 07e3b3d50cb234a4ba37cd711fafcafbcca7afc06a8fc033d0b4aab796a8d21e
font_02_sfnt_off0000f610.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF610 16256 bytes
SHA-256: be3ad3a6cb92645dc3d02289d08ca5f2a4cc0d9c30a531829022332c1c85537b