Malicious PDF — malware analysis report

Static analysis result for SHA-256 a088b31b5b8d90ce…

MALICIOUS

PDF

82.1 KB Created: 2021-08-16 12:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 70603d5f6a9b86e8ae3209402baa5663 SHA-1: 08cc2d90518ee491b656874e0797070f07278ddb SHA-256: a088b31b5b8d90ce957ad5dab299d2222e00823f42f6fe30c64691843b572977
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing a link farm that points to numerous other PDF files hosted on compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The presence of multiple external URIs and link farms suggests an attempt to obscure the final malicious destination or to manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/30cea5db61fe83cb29848f34ea16361a/55200130950.pdf In PDF document text
    • http://ya-ke.cn/admin/upload/66559651488.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/guwigofome.pdfIn PDF document text
    • https://burgas-remonti.com/userfiles/file/donexakamutage.pdfIn PDF document text
    • https://thedestinbeachhouses.com/wp-content/plugins/super-forms/uploads/php/files/f1b364b47025faef8286b7df11c97c16/3728147864.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608391fe5dfd7---81570284461.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/81410370883.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/25393926361.pdfIn PDF document text
    • http://aucoindeshalles.fr/menu/file/51024236733.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/da14a2451a7e47f5edd03f1db403ec42/tapogesafeguf.pdfIn PDF document text
    • http://akinmedikal.com/uploads/file/1047573450.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c66c1775976---viwazadarefatuzupako.pdfIn PDF document text
    • http://happypalettebnb.com/CKEdit/upload/files/gapefogorilojosepubon.pdfIn PDF document text
    • http://tomaszfilipczak.pl/userfiles/file/minodewujenesu.pdfIn PDF document text
    • http://gleneaglehoa.org/images/file/86399455317.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/1bcd8e2bb3290ba5a1425439388884e1/vimebevus.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/dvqfksb8eh41dh95i5kqlfofep/62064628274.pdfIn PDF document text
    • https://hgb.se/filer/file/rolazemokazeme.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/lazuduguzuzuxisofom.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/17130699066.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16077b7730ded0---48171720015.pdfIn PDF document text
    • http://tmtechvn.com/webroot/img/files/56371652478.pdfIn PDF document text
    • http://esistore.lu/userfiles/file/87391650853.pdfIn PDF document text
    • https://circolodelpistone.ch/userfiles/file/8950897102.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/gotikelige.pdfIn PDF document text
    • http://liberty67.com/clients/41815/File/5936335035.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=star+wars+ahsoka+castPDF 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_off0000df1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f732.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF732 10208 bytes
SHA-256: 13a97bb1ffad347d23c44b31528f2b865b60d35e028f25441d2b995173709789
font_02_sfnt_off00010e50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E50 16792 bytes
SHA-256: f792d5fd38fd980cc49e92dc5a198122e77b992a4e6ed09bf33c592499733f12