Malicious PDF — malware analysis report

Static analysis result for SHA-256 987827cb1f48dae6…

MALICIOUS

PDF

75.6 KB Created: 2021-09-25 01:01:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 39a5e46555cc23a91686978bf3e6d47a SHA-1: ff6937c975d64e87298bce7eb6b08c49753ae62b SHA-256: 987827cb1f48dae67c2cd7909f5a5867c5641a22aa5bbd3dc2d3e9ce3f0ff408
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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 appear to be part of a link farm designed to redirect users. 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 these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://drafthe.ru/uplcv?utm_term=the+psychology+of+love+sigmund+freud+pdf PDF link annotation
    • https://brincandoeaprendendo.com/fotosempresa/files/kirebegalatugakimetobo.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/gesibodopedabelukidefime.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/66265898621.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/pimotodawegarom.pdfIn PDF document text
    • http://szcftz.com/upload/desodasow.pdfIn PDF document text
    • http://satthachkhe.vn/image/file/sefonenawes.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/kedebekunuz.pdfIn PDF document text
    • http://ipea.kr/userData/board/file/61767578288.pdfIn PDF document text
    • https://airbays.com/userfiles/file/78868324557.pdfIn PDF document text
    • http://fillaracingacademy.cz/ckfinder/userfiles/files/xitanux.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/magax.pdfIn PDF document text
    • http://lishasurgical.in/ckeditor/ckfinder/userfiles/files/solovedibipigasan.pdfIn PDF document text
    • http://faradtvandor.hu/picture/userfiles/file/41253738474.pdfIn PDF document text
    • https://osikovo.eu/webroot/img/content/files/kexogilanozupimewej.pdfIn PDF document text
    • http://sziazsauto.com/uploads/files/67384264194.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/bf34a5c84f16f575bf34a7b5f2c2c8d4/49850315636.pdfIn PDF document text
    • http://nemochem.cn/upload/files/wufag.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/93578495962.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/8038504018.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/21290113918.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/xokuliwer.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16146ac064f427---66398145509.pdfIn PDF document text
    • http://hulstcustoms.ru/uploads/files/93611892367.pdfIn PDF document text
    • http://clubselectionvoyages.net/images/file/gilem.pdfIn PDF document text
    • http://suvenirzp.com/uploads/files/3442743020.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_off0000bb2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB2F 19780 bytes
SHA-256: 499eff758a8cdb89a341de0baff680f26d8e0fff1674c735d06e9803f35fa15f
font_01_sfnt_off0000ef06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF06 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001071d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1071D 11052 bytes
SHA-256: 6504daa12b9847c709c761234e5305a53f58ebd25ce2443dbd8fa728b6f05033