Malicious PDF — malware analysis report

Static analysis result for SHA-256 277533977553983b…

MALICIOUS

PDF

70.7 KB Created: 2021-04-08 19:09:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: adcf43b0b5bb2ee83f15d66126831348 SHA-1: b46631d09e05fce860d164caf5039f94a3149fe6 SHA-256: 277533977553983b6e647990c2ef4d0eb8cb83615e4b0d7f5fa88f851cd30795
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains or are structured as link farms, suggesting an attempt to redirect users to malicious content. The document body, though heavily obfuscated, contains references to 'market basket analysis pdf' and the authoring tool 'wkhtmltopdf', indicating a lure to disguise the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://ambrose.edu/sites/default/files/webform/zabufenopi.pdf In PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/1653940235.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/taxevoxasubosiwugudabi.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/lajeriz.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/mogewewe.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/60015669747.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/xubapubawaral.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/nutuzisujobipusife.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/2944445507.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/47147916176.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/6948618973.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/27804174203.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/DOqCt-cVA4I/uplcv?utm_term=market+basket+analysis+pdfPDF link annotation
    • 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_off0000d766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD766 5348 bytes
SHA-256: 2a720fd30c50dd59721fc0b8dff8f8f4915822ffdaa4704d13764729bbb26117
font_01_sfnt_off0000e9b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B6 10812 bytes
SHA-256: df5f584188672bd6ce0e79425cdc2f80218b6bb85e76d4eee0bca133e5f440b0