Malicious PDF — malware analysis report

Static analysis result for SHA-256 23d7d93c31718e47…

MALICIOUS

PDF

65.0 KB Created: 2021-06-23 22:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 5742e40e94abf86a18bef24cdfe5b0a2 SHA-1: 5ae699c441e5841d2c416af0ecd3b6d327800d57 SHA-256: 23d7d93c31718e471a9aecaf402be2adce63e907556123bfe4cf555315b4e977
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be part of a link farm designed to obscure the true destination. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, suggesting it's not a typical user-facing document but rather a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://kolesnikov.pro/ckfinder/userfiles/files/febepovineraruzetuwime.pdf In PDF document text
    • https://kuepancong.com/contents//files/45845299842.pdfIn PDF document text
    • http://crmrealty360degree.in/userfiles/file/pusolisukazimitifep.pdfIn PDF document text
    • http://aps-mes.com/files/file/lubigux.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%252Ffile/74707535682.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c73fcfc5c---kavesepup.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d1ae740df81---62625857814.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/7a1ce9e0f7c78262fa9e7247b31485d8/51188701317.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/oevoi2m96sig4chf0p9o4ea8l2/98217168787.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073090b63cd7---lagupuvexobogapoze.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160853fe612098---bodarogogawimoxumexujodi.pdfIn PDF document text
    • https://kovosluzba-praha.cz/res/file/telafemupomorejoruxapudak.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1608ceacac8ce4---sonumaladetofiwu.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/9ec82185fc5e4232d474b4cd95cc561e/49773857437.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b30698404a---rigoxuzomulolijakatopexa.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608b92a385804---64783583512.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210610071517182.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=2+minutes+and+30+second+timerPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CE 5396 bytes
SHA-256: 0e76c23fbeb552e6414ab9b87e8c9345ca819e378f86fa1250aea9cd7b4892ea
font_01_sfnt_off0000d40e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD40E 10348 bytes
SHA-256: 1ed2bf2e688c133b4c3e8c5b8a1cccd938260032832bce93a1cecf978ccc9b57