Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55c4007d97396fb…

MALICIOUS

PDF

68.2 KB Created: 2021-04-15 02:46:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 798f7176dca8505af50686b788572eb5 SHA-1: 4b5f5cf3f7b24cd7211cb187a4a358b6b4c451f4 SHA-256: a55c4007d97396fb4d649f2bac7594de319f2c234b2b46a4efb412856eb7cd04
126 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection, indicating malicious intent. The document body contains obfuscated text and embedded URLs, suggesting it is designed to trick users into visiting malicious sites or downloading further payloads. The presence of external URIs and link farm characteristics further supports a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://www.jwico.com/sites/default/files/webform/pagijan.pdf In PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/72246142748.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/66271497470.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/woluweweketasuzizolog.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/85138354947.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/34904816646.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/zolevijovexoneda.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/86947183128.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/vinuriruxelapaviwona.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=tafsir+ibn+kathir+english+volume+1+pdfPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/pelafo.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_off0000cd3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD3E 5720 bytes
SHA-256: b164c3945e5a07b586d67ca205c856337a8ddccba5013e53cf8e07f463f8f385
font_01_sfnt_off0000e099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE099 10660 bytes
SHA-256: 6d0a612f1a041fd02a410ba5cd2b64ba5f9c693f6bc13835f4e42e7e9be595a3