Malicious PDF — malware analysis report

Static analysis result for SHA-256 75882835a2466b20…

MALICIOUS

PDF

68.3 KB Created: 2021-04-27 10:51:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 48575698a3ec52a408b60a5eb4f3aa60 SHA-1: a78b2d42b072c7930c3c7d49aea66adfd7526d03 SHA-256: 75882835a2466b209bdb02d8d9030bdd0848ea76f8617cde9f8146d8a0a4a152
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple distinct domains, with a high ML classifier score supporting maliciousness. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically points to a non-clustered link farm on disposable hosting, suggesting a phishing or malware distribution attempt.

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 http://portal-mysigma.com/system/files/student-proof/41429692510.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/80411930416.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/bofuwidesuxugebogaxa.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/vuvosiritixulufanili.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/nibobuzokojovafizuza.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/17423244846.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/tawapiseligimagawawujimo.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=is+wd+my+cloud+home+secure+2020PDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/sametuzovu.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/63066688876.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/56905881998.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/68382108709.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_off0000cd7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD7F 5372 bytes
SHA-256: 0f2cb0309c8cd5d4ba7b3665fe168d935153c3e4061478b28b70bf5ae996543f
font_01_sfnt_off0000dfb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB1 10860 bytes
SHA-256: f377e0ade6bcb9033d15098c4846667f5bbbe5f5a858dd933cb4b21f85f79ca4