Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8cd59b6d227f85a…

MALICIOUS

PDF

74.4 KB Created: 2021-09-14 00:31:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ed83fdaf54fd5f8abf9ca3ceefbbb425 SHA-1: 15b1557bef807057668e8571d7d85a11f28564ca SHA-256: f8cd59b6d227f85a2e4806a7e6eb06c944adcf047d7d0fa4941f64fe50a86dca
126 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 a large number of embedded URLs, many of which are hosted on disposable domains and utilize UTM parameters, indicating a link farm designed to redirect users to potentially malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://laborke.ru/uplcv?utm_term=films+beginning+with+u PDF link annotation
    • https://biographiewerkstatt-singer.de/userfiles/file/wibunukalibomumakeg.pdfIn PDF document text
    • http://www.horakgolf.cz/ckfinder/userfiles/files/wizul.pdfIn PDF document text
    • http://studiomanzella.com/userfiles/files/vovonufigujasuwugejesava.pdfIn PDF document text
    • http://mascotdd.com/file_media/file_image/file/rugewogobibudububozazaji.pdfIn PDF document text
    • https://soroptimist.be/oldsite/intranet/ckeditor/ckfinder/userfiles/images/files/nunotuvamidewifud.pdfIn PDF document text
    • https://huangs.tw/uploads/files/202109071920324782.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/11338351467.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16130e7134fd81---fegezerixixuwonola.pdfIn PDF document text
    • http://baihsad.com/userfiles/files/20210911_200440.pdfIn PDF document text
    • http://ketnoikienthuc.com/upload/files/nazimasaxesu.pdfIn PDF document text
    • https://ijpdua.com/contents/files/gejamananidap.pdfIn PDF document text
    • http://yongchengtech.com/uploads/files/202109071358322411.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/tomiwezakuxetirokujuni.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/bigapizepijinife.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/bonafomaz.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/divepagutesugozumeletofe.pdfIn PDF document text
    • https://avukatwebsitesi.kocgrafik.net/upload/files/28930115065.pdfIn PDF document text
    • https://liepasmuiza.lv/userfiles/library/momudigavetif.pdfIn PDF document text
    • http://sun-dr.com/uploads/files/202109130122503271.pdfIn PDF document text
    • https://manenshop.com/upload/files/gobuvugiwawijigexejujugaw.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/24173709137.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/lixegaxavutidixaz.pdfIn PDF document text
    • 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_off0000bfc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFC5 10476 bytes
SHA-256: 79c7693c6b4c148366a0d4de7fb9145af309fb2b4c9e0468549c89f80cde391a
font_01_sfnt_off0000d761.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD761 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF73 17416 bytes
SHA-256: db7bfe965a80a500f2a10654ef143dc116a965e12bff9208560c03c4d5814409