Malicious PDF — malware analysis report

Static analysis result for SHA-256 6557eed9831de1bd…

MALICIOUS

PDF

77.6 KB Created: 2021-09-08 06:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8d736077f369f9d80e5ec7466e5231dd SHA-1: c834e7ee19220c24ac3a4d7bc70a9001103e94dc SHA-256: 6557eed9831de1bd51f4a8a8908857a6a6122eedfd29c96156c892fe5564caab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=organizational+behavior+mcshane+free+pdf PDF link annotation
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c1c7f6b8e8b---19549820724.pdfIn PDF document text
    • https://thinkhigh-tech.com/d/files/timemaxizuveven.pdfIn PDF document text
    • http://sattamatkapatti.com/userfiles/file/2649377368.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/4097503080.pdfIn PDF document text
    • http://liveisagenix.com/ckfinder/userfiles/files/95641717893.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/95041be6787eee9fbfa912b157a0e7dc/juwajanorerurinasifuw.pdfIn PDF document text
    • https://www.wemservice.com/ckfinder/userfiles/files/kejitajimuw.pdfIn PDF document text
    • http://okzawidow.pl/img/upload/files/31563235624.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/44055034669.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/28300770455.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/zijivewan.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/55136238564.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/63780220069.pdfIn PDF document text
    • https://shoreluxurylimos.com/userfiles/files/74534093302.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0cff69b224---58735737955.pdfIn PDF document text
    • https://www.cifphosteleriayturismo.es/ckfinder/userfiles/files/1273347688.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/92as172j8oggvoke63ka19jcn6/wekafebekaka.pdfIn PDF document text
    • http://toastwarenhuis.nl/app/webroot/files/userfiles/files/ribugezozi.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612c83ba4e5ec---30569086325.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/705602367cfa164cc17878b3d0cf9aef/96603500673.pdfIn PDF document text
    • https://mobilieroccasion.fr/uploads/file/35507249923.pdfIn PDF document text
    • http://nenkin-t.com/upload_img/ck/files/79774504110.pdfIn PDF document text
    • http://rauvuonsach.com/images/uploads/files/49018443282.pdfIn PDF document text
    • http://uptownfallschurch.com/uploads/files/45498499153.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_off0000c9fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e20e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20E 17076 bytes
SHA-256: 153c346742e3d9059e35ebcf1999663b571bce86a105fb0d4989c83858d21cad
font_02_sfnt_off00010e2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E2C 11360 bytes
SHA-256: ee2733c83717af03204d2b5681d46d4a866ac632c18e19b8735273f03d6d17be