Malicious PDF — malware analysis report

Static analysis result for SHA-256 f557d40edbbc8d9e…

MALICIOUS

PDF

86.0 KB Created: 2021-09-19 13:33:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 75c6a354807c387eb2a094ff930f7ddc SHA-1: 20fb432c24c8513edb181f7c30bd5870acc0c4af SHA-256: f557d40edbbc8d9e07cc57a6c9c1e3c37106e1b513435bddcb2a00995866b3ad
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to PDF files on various domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates a malicious intent to obscure the true destination or distribute content through a network of disposable sites. No scripts were extracted, but the structure and heuristics point to a phishing or malware distribution campaign.

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 https://ixiu-23.com/uploads/files/202109012158593572.pdf In PDF document text
    • http://akcjonariusz.com/UserFiles/file/darekefo.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/nefofefovego.pdfIn PDF document text
    • http://garderoba.sk/images/_file/wipizametapek.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/19203598720.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/9578074197.pdfIn PDF document text
    • https://llbyggodesign.se/UserFiles/files/xokozimizuxopuni.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614416df3576c---92907414315.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/sajonovipabogurejow.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/jaxufujomavowubitube.pdfIn PDF document text
    • https://kolorubursztynu.kolorubursztynu.pl/web/uploads/files/mobimo.pdfIn PDF document text
    • https://affordans.com/ckfinder/userfiles/files/ronagezupu.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161371fadc42c3---jumidaxesijarirogerizejim.pdfIn PDF document text
    • http://ke-sen.com/userfiles/file/1631686559.pdfIn PDF document text
    • http://studioprogettoarchitettura.eu/userfiles/files/86467986407.pdfIn PDF document text
    • https://davaocarrental.com/images/file/8698495546.pdfIn PDF document text
    • http://altronic.pl/!mag2011/userfiles/file/48756444226.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109070628055016.pdfIn PDF document text
    • https://dom4m.com/userfiles/files/46083807460.pdfIn PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/19524701019.pdfIn PDF document text
    • http://lsmtrontractor.com/upfiles/file/20210903113824.pdfIn PDF document text
    • http://baocaosudanang24h.com/uploads/image/files/73117640745.pdfIn PDF document text
    • http://jafra-com.at/userfiles/file/17029709212.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/variporofoke.pdfIn PDF document text
    • https://voyageaventurenepal.com/upload/files/jazurekibedapewunowa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+to+set+wifi+password+in+android+mobilePDF 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_off0000e8b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B6 10876 bytes
SHA-256: c5e1748cde1bd5b92086138c56b7dadf6d346cf5619aef7b1b3257c360e0c467
font_01_sfnt_off000101a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B5 18464 bytes
SHA-256: 63dd21f49fa0bd17a6d2833041dd5938317d3ec02d342dc9e289ee276c918b0d