Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b232d5681d3576e…

MALICIOUS

PDF

72.6 KB Created: 2021-04-15 05:35:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: a26c4cd407e4f3ef29e036785704bd80 SHA-1: 224cdcb5b624685f38877faa8bf49ce0f083dd47 SHA-256: 4b232d5681d3576eeea43aee7aa06a1ec0bc0fb5dea79fceb47b686224252831
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some of which are hosted on potentially disposable domains. The embedded URLs and the document's structure suggest an attempt to deceive users into visiting these sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://vectorcorp.net/sites/default/files/webform/resume/sabaw.pdf In PDF document text
    • http://seiary.com/sites/default/files/webform/rec/55418097166.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/mupiroto.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/jebumimebugamoto.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zajufofagobixipisuna.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/42042694998.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/2923424149.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/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=the+apocrypha+booksPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/20850651402.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/vabomabexajamoja.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/ziwilijevugibapuvoboka.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_off0000e163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE163 5244 bytes
SHA-256: cf41578d32a380a062e08160ef7ddab63269bd461f2654051d34bc5c1b0928d3
font_01_sfnt_off0000f331.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF331 10244 bytes
SHA-256: 92bebd649747197f35246b7c091eed980e69e113c25ac388a8a676c0bb5e9e61