Malicious PDF — malware analysis report

Static analysis result for SHA-256 e31057709f918b7c…

MALICIOUS

PDF

83.7 KB Created: 2021-09-14 00:08:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0600adc245d2b0eef5186113689377a1 SHA-1: 42754b73167a92c684ab7635a9201ba0422e65b0 SHA-256: e31057709f918b7cc79e236a72bf4be1037e6525259711a33e1895af2d09e9aa
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially malicious PDF files on various domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://drivescuolaguida.it/userfiles/files/5804993196.pdf In PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/91575537590.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/43951138646.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/kofatem.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/10659378166.pdfIn PDF document text
    • https://angkalaris.com/contents/files/lekapodepivabevob.pdfIn PDF document text
    • http://aviatechinform.ru/sadm_files/tadipejolifutiwelap.pdfIn PDF document text
    • https://pmsp-me.com/userfiles/files/rufewu.pdfIn PDF document text
    • https://excellencetogether.com/img/files/file/forigutemowimukonapozes.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/gilovewejifejafowifaxo.pdfIn PDF document text
    • https://villatoscana-pi.it/userfiles/file/11025680624.pdfIn PDF document text
    • http://hoangnampte.vn/quangbasanpham/app/webroot/upload/image/files/vixeronevuvegexipolag.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613467f8a928a---depip.pdfIn PDF document text
    • http://polyalpan.hu/_user/file/23254939803.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/98019496484.pdfIn PDF document text
    • http://damvua.com/damvua/public/images/files/torud.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/56254587162.pdfIn PDF document text
    • https://stcc-sa.com/motakamel/Ups/files/57871111574.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/45158908350.pdfIn PDF document text
    • http://qiangka.com/ckfinder/userfiles/files/semamadibesurezipawiw.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/4c2e52db3936bfa73cbae35ca787fd43/lepakepozovobejo.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/30083880426.pdfIn PDF document text
    • http://77owship.netsociality.com/upload/files/15694077150.pdfIn PDF document text
    • http://ebiocell.com/uploadfile/file///2021091300093054.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/12594157777.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=on+the+next+episode+of+dragon+ball+zPDF 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_off0000dbb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB9 11104 bytes
SHA-256: efcc1e07ced61b678e6d9320731bf1efb864f2b32ebdfa0a7fd3706ed9ac052c
font_01_sfnt_off0000f52f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF52F 19680 bytes
SHA-256: 48acac23024c5bea575668a43e00efd31e1de60ebdfe96d6add3246d8e441d20
font_02_sfnt_off000128db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1