Malicious PDF — malware analysis report

Static analysis result for SHA-256 39a4b86f078a61a3…

MALICIOUS

PDF

79.9 KB Created: 2021-09-01 08:20:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ffadc1eaf930708a19bb13f0a8681d65 SHA-1: f69b467a7884cc1727c6ff8400b68ca6224d7265 SHA-256: 39a4b86f078a61a321e3ff4ac5b5e8ca6ffe06fc546eae35e56536b3df33da09
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous URLs pointing to compromised WordPress sites, suggesting an attempt to lure users to malicious content or phishing pages. The primary function appears to be redirecting users through these compromised hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e613a88847---vuxarazilafupu.pdf In PDF document text
    • http://csc0512.com/userfiles/file/20210731054528_2ecsag.pdfIn PDF document text
    • https://travolution.travel/wp-content/plugins/super-forms/uploads/php/files/c08add3ba8963fc7709be9484e24c236/pediburivitofunonugeba.pdfIn PDF document text
    • http://muntepa.com/userfiles/files/wifuxenananel.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/rogel.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/zokimo.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/rugaxapibegu.pdfIn PDF document text
    • http://wxhsbl.com/ckfinder/userfiles/files/20210723_061839.pdfIn PDF document text
    • http://casier-a-bouteilles.com/file/dukena.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec70f6dcb1---xirogusigolutigej.pdfIn PDF document text
    • http://alacarte-grafik.de/userfiles/file/82010244929.pdfIn PDF document text
    • http://stlukesmn.org/clients/17773/File/kiwonirenilozupuxeg.pdfIn PDF document text
    • https://www.qualityitalia.it/ckfinder/userfiles/files/64910572653.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/kadovasor.pdfIn PDF document text
    • http://valifyrepapillon.com/clients/6/68/68e1c6a84db99a04c21676ff826d6e37/File/7720412015.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16093c5b7da23c---pakub.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/fogirujabiwuzenowibiru.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/94354368408.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160929378b0053---79205241618.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/voxetadizexurotabugif.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080e3c0de897---53677331684.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021082210034673499.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=discrete+joint+probabilityPDF 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_off0000ce93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE93 10752 bytes
SHA-256: 2a270c5db7b7d833d1953f3d160b2ba64d2b1e8755182ffaef2bb9b5b31566e4
font_01_sfnt_off0000e72d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE72D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF3F 19044 bytes
SHA-256: e22bdd632d83190051612ea8fba8d8651d990061ef78f41950f1501ec992f8f8