Malicious PDF — malware analysis report

Static analysis result for SHA-256 5500c888db94a1ad…

MALICIOUS

PDF

75.8 KB Created: 2021-04-18 22:04:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: e8b00b4ea510f002b34aae8e93428671 SHA-1: 16b9a612efc9ea5e725cb32916d6bc84b8dbd7cc SHA-256: 5500c888db94a1adf8be263efed4a5d0bb690b380b3f3c9e40c87140794883a9
126 Risk Score

Malware Insights

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

The file is a PDF document identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to seemingly legitimate domains but are likely part of a link farm designed to obscure the true malicious intent. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests a tactic to evade detection by distributing links across many domains. While no scripts were explicitly extracted, the PDF format can embed JavaScript, and the overall structure points towards a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://www.guninetwork.org/system/files/webform/heirri_proposals/gafazibo.pdf In PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/sabaw.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/54003515034.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/95133977644.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/52872338461.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/99284441703.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/lerudaxalopavowurugepoviw.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/newusagolepilukakatukus.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/manejuwavujegajejumoxak.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=arduino+projects+book+pdf+espa%25C3%25B1olPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/zuwamusijugowop.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/68272747422.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/pelafo.pdfIn PDF document text
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/52983615418.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/sukazejaso.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/wetesagepe.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e730.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE730 5632 bytes
SHA-256: c118a99a125bc10a99028221a50ed5e90727184db4e957830f5c60810dabff39
font_01_sfnt_off0000fa27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA27 11732 bytes
SHA-256: 9bc89614f789d63cc380f4f42ccadd82d92b428fb1c1390efd5cd23be7aed292