Malicious PDF — malware analysis report

Static analysis result for SHA-256 645056c6f585217a…

MALICIOUS

PDF

84.7 KB Created: 2021-03-03 23:41:19 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 6b506b6cccd17d0e78e15c717a408d36 SHA-1: 74c8e5f2ca4c6ba323a29c22ef17cfea093d4273 SHA-256: 645056c6f585217ae483870bad658e50ad5e5f13995b8603e40a375c3aec50be
184 Risk Score

Malware Insights

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

The sample is a PDF file flagged as malicious by ClamAV and an ML classifier. It contains numerous embedded links, with at least one pointing to known malicious redirector infrastructure (https://dafemum.ru/wix). The PDF structure and link farm heuristic suggest an attempt to lure users to external sites, likely for phishing or to download further malicious content. No scripts were extracted, but the presence of malicious links is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://dafemum.ru/wix?keyword=chris+craft+327f+engine+manual In PDF document text
    • http://genokoti.iblogger.org/8230327825.pdfIn PDF document text
    • http://raisinshub.club/12233032819660xr.pdfIn PDF document text
    • http://gijixig.22web.org/sonda_vesical_enfermagem.pdfIn PDF document text
    • http://katagonubazi.22web.org/gukigabirewavuranupejimow.pdfIn PDF document text
    • http://kuvewumewatono.22web.org/bafawifo.pdfIn PDF document text
    • http://idealslimitaly-ufficiale.site/zolufabuloxatexuzaretuddlxk.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gizenelik.rf.gd/wumadakeleser.pdfIn PDF document text
    • http://xalanijowule.rf.gd/emirates_id_renewal_form.pdfIn PDF document text
    • http://fotopokidag.epizy.com/block_business_letter_format_template.pdfIn PDF document text
    • http://sajumapudetuji.rf.gd/barefoot_investor_online.pdfIn PDF document text
    • http://fitatina.rf.gd/5807371152.pdfIn PDF document text
    • http://dipomik.epizy.com/biohazard_waste_disposal_guidelines_uk.pdfIn PDF document text
    • http://misugivunuzu.epizy.com/divorce_settlement_agreement_template_maryland.pdfIn PDF document text
    • http://begodep.epizy.com/sikemixumisi.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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00011cc6.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x11CC6 23216 bytes
SHA-256: 735e04d285007e137ecc01d7dcbd9eab9979c599df9ffc35f2e22d653968c3c2
font_00_sfnt_off0000e679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE679 5576 bytes
SHA-256: abc5e8dd71a17d42e632c93ad46cdc1683c02e124673d7a944f2412968546194
font_01_sfnt_off0000f94a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF94A 10324 bytes
SHA-256: d729accfcd754a6b0ceb4eed28eb43f3f7aeea32585ec7b30ae5d15d2b613dfc