Malicious PDF — malware analysis report

Static analysis result for SHA-256 858142bd90bc4764…

MALICIOUS

PDF

70.6 KB Created: 2021-10-14 01:44:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d5c57d16c19a4555d8cf8bc5f40e4b12 SHA-1: 1ee772602dd8d020dcfe4c0c70dbbbbeb852baaf SHA-256: 858142bd90bc476465a9a75bfa6e2a6232f12d8b7d6604db5c9e14d6087e98b7
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 pointing to a link farm, indicating a likely attempt to redirect users to malicious sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, identifying a pattern of disposable hosting and UTM parameters used for tracking redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mr-alian.com/upload/ckfinder/files/770001903.pdf In PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/bukofewirafubu.pdfIn PDF document text
    • http://ganteltechnology.com/system/userfiles/file/94761687231.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/rexofidasa.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/6ca8aa607c4aaf92df0ae251e07ac837/xutisesipireroz.pdfIn PDF document text
    • https://veriniams.lt/userfiles/file/pasapuwifemolibulajogowo.pdfIn PDF document text
    • http://cabini.it/userfiles/files/79154900229.pdfIn PDF document text
    • http://otpetye.com/images/shared/file/pujudobobojexij.pdfIn PDF document text
    • http://ccsl.asia/files/6933884064.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/33564428142.pdfIn PDF document text
    • http://bollnas.boj.se/uploads/userfiles/files/vatenusesogakizonelari.pdfIn PDF document text
    • http://jbdclothiers.net/emailer/userfiles/file/logatonavosipisiv.pdfIn PDF document text
    • http://alompar.hu/uploads/content_files/files/vawuzukajewaroxovobewaza.pdfIn PDF document text
    • http://bubb.cn/up_file/file/lesejejare.pdfIn PDF document text
    • http://chikatere.com/Upload/files/godatezepubibog.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/3903728259.pdfIn PDF document text
    • https://globalcareerclub.com/FCKeditor/userfiles/file/luturamutukaf.pdfIn PDF document text
    • http://smepil.com/ckeditor/userfiles/files/tuwub.pdfIn PDF document text
    • http://gzbaosui.com/uploadfile/files/21919365604.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1614b19f885a1b---89953554063.pdfIn PDF document text
    • http://kpghomerepairs.com/uploads/image/files/5859473152.pdfIn PDF document text
    • http://wksx.top/images/userfiles/file/9624102501.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/wamojugefudebi.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/2I9n2o-U8HI/uplcv?utm_term=qualifying+adjectives+listPDF 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_off0000b37a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB37A 15984 bytes
SHA-256: d56556601a5d0aa4d1138bc742f9960c50edf3a1a376ef26f5efcbadb8bf453b
font_01_sfnt_off0000dbab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f3c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C2 10900 bytes
SHA-256: d7a9333b6e5a97d62fc8e881438a307645b16fc76986ffc811825ccf441f01ef