Malicious PDF — malware analysis report

Static analysis result for SHA-256 816b6f37b9c27901…

MALICIOUS

PDF

79.9 KB Created: 2021-09-21 09:46:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b8fe1fb1a9f9b274f30f978336c9c0c6 SHA-1: a2b9990cfbc98b6974101d94c5589cfd70b1bfc4 SHA-256: 816b6f37b9c27901bba69cf50e80f0303e33727ad51064f8bd42ffc8007a82b2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links pointing to potentially compromised websites and disposable hosting, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161399719adff7---27485424993.pdf In PDF document text
    • http://onnetsolution.in/userfiles/file/37849421420.pdfIn PDF document text
    • https://thegmsbihta.in/userfiles/file/ragin.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210917020421.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/88359773976.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/83be57e6a999a8347bd906d5c25b290b/gabewulilipizoloxijut.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/83103321467.pdfIn PDF document text
    • http://teamtrinity.net/trinitya/file/zasolezukirogafuvagi.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/a39ff33972894bb66a49b6285925056e/jamax.pdfIn PDF document text
    • http://linker-apps.com/files/damezuxikobilaxule.pdfIn PDF document text
    • https://manage3.realtourvision.com/rtv/ckfinder/userfiles/images/files/jawafafuruxafudo.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16134ade0258ed---wowizenomolefugupiti.pdfIn PDF document text
    • https://5ky13lu3-1251.com/contents/files/gekabadowewexetoxera.pdfIn PDF document text
    • https://tessuno.com/upload/files/6136ac8fb2017.pdfIn PDF document text
    • https://mjrspot.com/fckimages/file/famebazoletisi.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/49416464328.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/40744420694.pdfIn PDF document text
    • https://kocarbonag.com/luutru/files/panegugofakudetobawuli.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/b64jp9ps22t71u2lm028hsehg4/4407132602.pdfIn PDF document text
    • http://linhkienhunganh.vn/luutru/files/20155800260.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/669vsn9gt4u07cdtneq9ji2kj6/91051816129.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xixeraliwululiguriken.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/20542810525.pdfIn PDF document text
    • https://31app.com/userfiles/file/litobuliso.pdfIn PDF document text
    • http://mtsp.by/userfiles/files/rakuromal.pdfIn PDF document text
    • http://saydersan.com/firma/files/47179318814.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=benefits+of+using+technology+in+businessPDF 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_off0000d6d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6D6 10760 bytes
SHA-256: db96e81e3813a41498309d8c60a1a1961be97472ea3da80e4505b30f4d8eb9c0
font_01_sfnt_off0000ef9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF9A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107AC 16420 bytes
SHA-256: cd32a8f590f583574389caeaa9dd8ae06d3ea2fe65ce420e5e29f70efdb783fb