Malicious PDF — malware analysis report

Static analysis result for SHA-256 139973001fed4a02…

MALICIOUS

PDF

68.2 KB Created: 2021-04-20 20:05:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: cf458a4314746f8e7ff6c5f4697c50d0 SHA-1: 8aa0e0f299bf098b46660ff2e92c0aaf319df808 SHA-256: 139973001fed4a02b9930b9026d7f7351541b52e7ed0145b4ee37c2541acc829
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 or unknown domains, suggesting a link farm designed to host malicious content or redirect users. The document body, though heavily obfuscated, contains references to 'Groupme desktop download' and 'wkhtmltopdf', indicating a lure for software downloads.

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://www.enwidth.com/sites/default/files/webform/resumes/paxifufal.pdf In PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/bugoxugokerudanetisene.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/rijuluzevowogadabiwi.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/xojisipet.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/2944445507.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/kizosilubim.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/85138354947.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/nikosomonebazi.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/vetasitumuwogemukuruv.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/87762274679.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/S30rS-6n6vg/uplcv?utm_term=groupme+desktop+downloadPDF link annotation
    • https://lib.asu.edu/system/files/webform/90369837207.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_off0000ccce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCCE 5292 bytes
SHA-256: 8e676001abf5da9a90bd70c3fb57392d3b0b858cbed55104ea74422ac73165d4
font_01_sfnt_off0000decf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDECF 11048 bytes
SHA-256: 82465ab0b27525e0f6e6540ac69e7d64bdfc336cf38143327d6fd082947de321