Malicious PDF — malware analysis report

Static analysis result for SHA-256 1dd6f350816bdfc9…

MALICIOUS

PDF

66.1 KB Created: 2021-04-18 03:10:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 4c6f992fea3964269ec98603ac88fda2 SHA-1: 9497708a1c6d4b3b1c76e28284bc7c672fdf9e09 SHA-256: 1dd6f350816bdfc9495fe31df89a138d119c0f527bdbb7b3a48a3e50216a3c57
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, suggesting it is part of a link farm designed to redirect users to potentially harmful sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution attempt.

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.mothercare.ro/sites/default/files/webform/resumes/95866450710.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/71502920023.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vawutudujenopudup.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/67198091979.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/dovav.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/woxofenobe.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/95941620813.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/93477879009.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/69309865186.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/zateguzafafidefezibexe.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/55178968397.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/cv9VXjIrmdE/uplcv?utm_term=how+to+calculate+venturi+flow+ratePDF link annotation
    • https://www.vub.be/sites/vub/files/webform/86005813007.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_off0000c5b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5B0 4808 bytes
SHA-256: 0807a25e972472b06d98a6f6f550723ca790b61754809d0c45d24ebd794d6808
font_01_sfnt_off0000d631.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD631 11128 bytes
SHA-256: 75cc93a8c9b67de748268a2a30759642a8a4c2bdb17298fba6800b6881623d18