Malicious PDF — malware analysis report

Static analysis result for SHA-256 242c1592615ef18d…

MALICIOUS

PDF

70.7 KB Created: 2021-04-16 06:26:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 4553b7a1eee83999e2f78fba5ff637a4 SHA-1: b112c3f758b714cbe81758756172c09b0a257099 SHA-256: 242c1592615ef18da0b3a3f16792d7138b0c86504b64d05d2cd4f8bffdfed5f6
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by multiple heuristics, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs, many of which are hosted on disposable domains, suggesting a link farm or phishing attempt. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a worksheet title, indicating a lure to disguise malicious intent. The presence of external URIs and a link farm heuristic strongly suggests the document's primary purpose is to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.mainephilanthropy.org/sites/default/files/nikosomonebazi.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/55178968397.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/16831560309.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/30199048500.pdfIn PDF document text
    • https://www.viachristi.org/sites/default/files/webform/89070061484.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/5296457674.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/dovav.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/zupusozuxabodes.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/kokibilelage.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/pagasumoxozodaxatukaliwus.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/30150103061.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/49323480199.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/kutovaduro.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/meratasadif.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/dakorudi.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/12938533755.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/kupoxogij.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=domain+and+range+worksheet+%25231+answer+sheetPDF link annotation
    • https://campusrec.princeton.edu/system/files/webform/4552140304.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cd53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD53 5148 bytes
SHA-256: 3fcbb126a02c84c67989de32d99c3ab6ed8ce594198de4d6f18f8b80295e6e57
font_01_sfnt_off0000deb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB8 9676 bytes
SHA-256: 934518c865d5dde681f2c84834962019642262112dfb71258b614de99373e6bd
font_02_sfnt_off0000ff8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8B 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176

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