Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8f3da7c077a6c2c…

MALICIOUS

PDF

69.5 KB Created: 2021-04-19 14:15:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: d23874a2bad4cd73677cb2540b6e7445 SHA-1: da024b4c0113ff4aebc3f52ad3d6df4f19097e82 SHA-256: d8f3da7c077a6c2c8fd04be3ece5c65e1c1d9225eb93cd5b3a6bc2fe70d5b65d
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to various external URLs. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm heuristic point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://ambrose.edu/sites/default/files/webform/futexapepunuvanujom.pdf In PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/tawapiseligimagawawujimo.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/46846662681.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58588935603.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/setafemamuf.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/55178968397.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/31626011693.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/memirudomonejusowanasu.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/wijuwimitixatedus.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/50635107556.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/57515461030.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/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=htc+one+m8+case+walmartPDF link annotation
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/kozavexol.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/61493424170.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/xakunowegetudirojevogejiw.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/68876097481.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_off0000d384.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD384 5192 bytes
SHA-256: 0cef3b7dc9e0b7b6072bcaac332506c787d46c17725298f726d3a9b9a15ed3d5
font_01_sfnt_off0000e524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE524 10656 bytes
SHA-256: b6bc20c7a0dfa198ae58cf45415c231c658b171815642eba2678970c5c131e05