Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bfbb6ad55d003d5…

MALICIOUS

PDF

65.1 KB Created: 2021-04-14 07:18:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 8a51eaff96c47eee4016be7723d966f3 SHA-1: 1ac217a3117e1c55b68b132dbb614d1c1d0c71a7 SHA-256: 1bfbb6ad55d003d5b02d11e3037e4a739d857ba6ebf855ffb196affd431f6e6b
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to link farms hosted on seemingly legitimate but potentially compromised websites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high likelihood of this document being used for phishing or distributing further malicious content. ClamAV detection as 'Pdf.Phishing.Trojan' strongly supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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.natsihwa.org.au/sites/default/files/webform/72917344941.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/veser.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/mupiroto.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/wugibizipudaxejomite.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vinoku.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/topijetidilotifoga.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/21411595718.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/~3/1xuhb7AK25c/uplcv?utm_term=the+mind%252527+s+machinePDF link annotation
    • https://www.vub.be/sites/vub/files/webform/pagilavamuvawasaxega.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/liwubuwivak.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/bidemuf.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_off0000c3da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3DA 5032 bytes
SHA-256: e790fe97645a9ef0f892490e3786c08ff4df8aa338e954250ac5d0c3cc7965a3
font_01_sfnt_off0000d4d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D6 10412 bytes
SHA-256: 16ce36f985599cb6be5558b2f3e3c6fdd4d41f521562c02efbb9d70a34f1440d