Malicious PDF — malware analysis report

Static analysis result for SHA-256 66fa57e0eec05861…

MALICIOUS

PDF

70.0 KB Created: 2021-10-02 14:34:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 1d7bde9afe03a26c407a54207395a74a SHA-1: 858631e80a973b9539c73bd3be8562db56ff91d9 SHA-256: 66fa57e0eec058616b247d2f515db53eb71f56ac697c627df0c35c1c8547fbee
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to external websites, many hosted on potentially compromised or disposable domains, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' reinforces the conclusion that this PDF is part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://chia4kids.ru/ckfinder/userfiles/files/98719293427.pdf In PDF document text
    • https://oncallanatomist.org/ckfinder/userfiles/files/82678196176.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/gapanivavuviw.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/1224837861.pdfIn PDF document text
    • https://siliconautomation.com/userfiles/file/57404905551.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202109030410079361.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/fba675817b5911fd5a17e09630aca50d/35463040491.pdfIn PDF document text
    • https://alharithiforcameras.com/ckfinder/userfiles/files/lejopefasamumugelubilovo.pdfIn PDF document text
    • http://www.jokilaaksonratsastajat.fi/file/74809778470.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/68765655435.pdfIn PDF document text
    • http://www.ppk-kp3k.kkp.go.id/ver2/extra/ckfinder/core/connector/php/media/ckfinder/files/zibuxutero.pdfIn PDF document text
    • http://cocoon-source-harmonie.fr/public/file/36682839957.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/25649559114.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/86991881516.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/13816399822.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/ffa3364bcfda4f7ca52927b72f13b4cf/kovofutumapomorexobofib.pdfIn PDF document text
    • http://palami.by/images/file/worelopikabamup.pdfIn PDF document text
    • http://willbramephotography.com/76321481916.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/42727826061.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/56093128213.pdfIn PDF document text
    • http://mskabel.cz/UserFiles/File/89484395208.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///fiwisasatebiwojajasidodal.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/e4d5f51b9ac692c8783f2ada7af37a16/52738018454.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+do+you+change+a+powerpoint+to+a+pdfPDF 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_off0000af77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF77 16504 bytes
SHA-256: 073c9a764a101bcbd2065a7ce544ae5ee4e861d3a12250c41c72061ed327c671
font_01_sfnt_off0000d8ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8EA 10976 bytes
SHA-256: 671f06eda3b1e8ad86e3e9ea501c1d64df7b78564034b6e8f929637fe9fabf71
font_02_sfnt_off0000f22a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF22A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1