Malicious PDF — malware analysis report

Static analysis result for SHA-256 45c363f8e8f78f25…

MALICIOUS

PDF

72.1 KB Created: 2021-05-23 17:12:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b7549cc65da9baa5ded65d60f788e3ae SHA-1: 458dc72225982f874f48b63c081203200e6c95c2 SHA-256: 45c363f8e8f78f2534de6af6e2105e79920eaab8872055a90945f0d7de7f5336
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable hosting, indicating a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to drive traffic to malicious sites or distribute further payloads. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a malicious document designed for traffic generation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://baarspo.ru/strik?utm_term=days+of+the+week+worksheets+for+toddlers PDF link annotation
    • https://rofewure.weebly.com/uploads/1/3/3/9/133999154/rezepufij.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370780/normal_601cee8b9e859.pdfIn PDF document text
    • https://vakuvovigoder.weebly.com/uploads/1/3/4/4/134467198/02e9f56c62b81f9.pdfIn PDF document text
    • https://giruwaferelesed.weebly.com/uploads/1/3/4/8/134850821/xageraximedukip.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423166/normal_6033cd794e676.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4498992/normal_601b1a183dc2d.pdfIn PDF document text
    • https://mazazujusuvazix.weebly.com/uploads/1/3/1/8/131856432/4711091.pdfIn PDF document text
    • https://zogoxakemu.weebly.com/uploads/1/3/4/2/134235374/776b9e09825.pdfIn PDF document text
    • https://goremafijitem.weebly.com/uploads/1/3/4/6/134617837/gurebiduronif_pokofekanox_turulamuw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473916/normal_602145a567c1a.pdfIn PDF document text
    • https://tugixafebav.weebly.com/uploads/1/3/2/6/132681891/gasawuloxida.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454803/normal_603aa1c6dc3ff.pdfIn PDF document text
    • https://tugiwosigef.weebly.com/uploads/1/3/2/7/132740290/zogabikida_vokefupo_sovogusire_doludijize.pdfIn PDF document text
    • https://xewulowew.weebly.com/uploads/1/3/4/7/134757629/kopolixaduxib_daruselo_zaketudagur_mufizawedexar.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4466675/normal_5ff03b172406e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/lomogas/java_string_format_int_leading_zeros.pdfIn PDF document text
    • https://s3.amazonaws.com/rufonali/five_examples_of_simile_sentences.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_off0000de49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE49 5252 bytes
SHA-256: a07b82ea542d33999bee7958ac16e6e6cba9f667e9fc71378d8e86ec12943aa0
font_01_sfnt_off0000f03e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF03E 10116 bytes
SHA-256: 937bd6f3fd976ee13de78f6412531373ddff174026ed64fde3df621d4cbf20d5