Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb9b7768a0313454…

MALICIOUS

PDF

73.8 KB Created: 2021-04-12 14:57:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 656eefbd6be2a75b1d43ebe3bad813a3 SHA-1: 2ca9cd2b024defa782465476e7b7e027d6d6bc64 SHA-256: eb9b7768a031345468907a5f0237746ee696627b1703973cbb4e92de8b657fc9
126 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, some of which are part of a link farm, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing attack leveraging external links.

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 https://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/70037852461.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/43403042061.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/55418097166.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/19026354442.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/lavajaruzapelusudixavu.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/10891008032.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/bulurifabisiwotubavigivos.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/~3/1KS0DP0cxss/uplcv?utm_term=samsung+galaxy+a+9.+7+reviewPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/25860956451.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/94207829768.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/21338807989.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/fapivo.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83328436210.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_off0000e21d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21D 5696 bytes
SHA-256: fc0b1d5ccd38db2a186e47a493d623d01edd1f328236d9bb1f6e56f7e1f8a72b
font_01_sfnt_off0000f588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF588 10988 bytes
SHA-256: ceef0ddd8c3b5593ab6ca54c2f94050b115c7630c0c9600ef46dc09b76418b41