Malicious PDF — malware analysis report

Static analysis result for SHA-256 b565dc452d6f41f7…

MALICIOUS

PDF

69.1 KB Created: 2021-04-08 16:23:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 7402e33add205b77c243db86a91dffb7 SHA-1: 91d29b5cfe8f86aa8c4aed84c2eab95fa54488cd SHA-256: b565dc452d6f41f7f73d7d13645eef954594716bf6edb00d92762c5515e4c114
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some of which are hosted on disposable domains. While no scripts were explicitly extracted, the PDF structure and the nature of the URLs suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

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
  • 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://ambrose.edu/sites/default/files/webform/82598578892.pdf In PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/87706268510.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xexazud.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/95374483905.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/21073527915.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/paxifufal.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/~3/3vuEKuznOb8/uplcv?utm_term=neologism+examples+pdfPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/vifixofixif.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/mevupuxapiledowitire.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/muvebijamalixodimobowase.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/zupedofijemurak.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/fasulegok.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_off0000d320.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD320 5300 bytes
SHA-256: c02bef7ab3ca48fcfd1455a932856503f4ac45c0cbd4bc08f60db52ef05173fd
font_01_sfnt_off0000e52b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE52B 10208 bytes
SHA-256: 7012b95b44bb2d7e46e2b571c0b40ff24b4bcaa31653796a0f7af2978f4fe1ae