Malicious PDF — malware analysis report

Static analysis result for SHA-256 b98b564d5b54081a…

MALICIOUS

PDF

73.0 KB Created: 2021-10-07 23:30:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 892f332cb58df5fb7703805c3e7f1d76 SHA-1: b3d91e08b5ff8fcc5f02bf7b5ff32d0b4b997f5f SHA-256: b98b564d5b54081ac9871e2c7a2af1fa7adbbbbe877bca70c5d431d181e71bf1
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 numerous embedded URLs that point to external domains, many of which are structured as link farms. The presence of these URLs and the heuristic indicating a 'link farm on disposable hosting' suggests the document's primary purpose is to redirect users to potentially malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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=antibiotic+induced+pseudomembranous+colitis PDF link annotation
    • http://kajo-frings.de/userfiles/file/3185096410.pdfIn PDF document text
    • https://semut73.com/contents/files/deserosurut.pdfIn PDF document text
    • https://andrejc.si/files/file/73865852104.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/sovifelogo.pdfIn PDF document text
    • https://blnk.eu/userfiles/files/golegafiwogonifaxanibed.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/gogosanekome.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/52979665129.pdfIn PDF document text
    • https://doan295doson.vn/namthuan/images/news/files/59071900234.pdfIn PDF document text
    • http://geasit.it/userfiles/files/23953576460.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/pupirazeburovilumamakob.pdfIn PDF document text
    • https://athensviptour.com/wp-content/plugins/super-forms/uploads/php/files/92e3edd4ef277cfb92c36aa65045f82d/kivubofumozosunexigonibeb.pdfIn PDF document text
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/32986475143.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/18085732283.pdfIn PDF document text
    • https://bio86.net/userfiles/fichiers/zagowepadinapom.pdfIn PDF document text
    • http://hunting.kg/userfiles/file/moroxizapelorinekoniw.pdfIn PDF document text
    • http://3qbuy.com/CKEdit/upload/files/xevodaz.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/63801094025.pdfIn PDF document text
    • http://xn--80affcyoc0ac1f6a.xn--p1ai/admin/modules/ckeditor/ckfinder/userfiles/files/nezidepidititimifoloweref.pdfIn PDF document text
    • http://mwbright.com/upload_fck/file/2021-9-14/20210914090854330919.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1613f8483bceae---nufijikoxoket.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/411247862.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/95413919858.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_off0000bdcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d5e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E3 10896 bytes
SHA-256: 3118097f5178ca19c0d4cf1a81f5b00ca2ffa8e8521ef35d6b78dca017a60a67
font_02_sfnt_off0000eee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE0 15684 bytes
SHA-256: fd0afc906e0d752e8ed41bec991b4477df4a761ed665a1d6e9d2d775ad5d4ec9