Malicious PDF — malware analysis report

Static analysis result for SHA-256 87598cf289c3ad3d…

MALICIOUS

PDF

74.3 KB Created: 2021-09-20 10:13:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0e9d90aa034832996303888ed0308da9 SHA-1: 55d70105f59441191837fbc2bd21d8ef8a50e06c SHA-256: 87598cf289c3ad3d9bc821dc0abc847e7b0c6a0511de264ee89ec3dc53d636dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous embedded URLs that point to compromised WordPress upload directories and other disposable hosting. These links likely serve as lures for phishing or to distribute further malware. No scripts were extracted, but the presence of multiple external links suggests an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://coretry.ru/uplcv?utm_term=ms+access+apk+download PDF link annotation
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/17f87lke67j885fpv7oeaivud8/55831526315.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/d25a698a0d69debbfa7a523dc6a3fa07/86762325002.pdfIn PDF document text
    • http://andreevka.topmebli.com/content/xuploadimages/file/32622331227.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/2f04ce482a6e12e5ae5c5fc90e9dfa19/8452447876.pdfIn PDF document text
    • http://connect-event.fr/ckfinder/userfiles/files/dutojorar.pdfIn PDF document text
    • https://decisionstogo.com/fck_image/file/61663292914.pdfIn PDF document text
    • http://klimagra.pl/images/wysiwyg_img/file/xenenetafasu.pdfIn PDF document text
    • http://mtsp.by/userfiles/files/93405326539.pdfIn PDF document text
    • http://sevgineslianaokulu.com/ckfinder/core/connector/php/uploads/files/bikemiwaralaxomasugovuxuz.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/jogikofukinu.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ae127713b68f88f6b613cc687368cb4b/zomawofatesit.pdfIn PDF document text
    • https://ratoempat.com/contents/files/fiwokitowotarugamiloma.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364b4d7d3e9---gipomapiradadelonetiwu.pdfIn PDF document text
    • http://malabarisproducoes.com/arquivos/files/govatazodasinev.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/59367708810.pdfIn PDF document text
    • https://www.xyoaa.org/sites/default/files/files/vorubizigo.pdfIn PDF document text
    • http://ride-on-earth.com/images/blog/file/supilefamizasobeziraz.pdfIn PDF document text
    • http://webcertain.asia/contentupload/fckeditorUploads/organization_/file/lapetuxojamunaw.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_off0000bd37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD37 17840 bytes
SHA-256: 34f77336b6cba108c586b248059ed2532d9fbc0ddcadab08bd6a91ebe80955a0
font_01_sfnt_off0000ec01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC01 10388 bytes
SHA-256: 87e631f0d05219db1005726f788c7a957eb7d856b023d4c9bfa60b738f51265a
font_02_sfnt_off000103bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1