Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fd2ec31ecc429d6…

MALICIOUS

PDF

70.5 KB Created: 2021-04-12 23:48:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 9d32c1f0e86382dee17673b64236b192 SHA-1: ac15a84842f13b32ca907062d2be514e20d7396a SHA-256: 3fd2ec31ecc429d67c76b43753b3237f9a38daab1c19dcc796105d6954e67010
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, a common tactic for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent. While no scripts were directly extracted, the presence of external links and the ML classifier's high confidence indicate a malicious document, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 http://oaklandchildcare.org/sites/default/files/webform/85278691340.pdf In PDF document text
    • https://europa-ts.ru/sites/default/files/webform/81905598419.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/lomaxitafuvutatu.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/42535902170.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/38059385999.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/kutovaduro.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/kanuvanirarotugawabu.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/sowasipaxezok.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/~3/6naE_Nh8_CY/uplcv?utm_term=skeleton+merchant+terrariaPDF link annotation
    • https://lib.asu.edu/system/files/webform/61431168480.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/rutepirunumobapof.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/zixulupuritijidegebi.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/ludazerubadariwevulefaxu.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_off0000d769.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD769 5028 bytes
SHA-256: 2b4558cfa0a55d6bcc89807016ff8731e524c362c49d34e9950528eff98bbf21
font_01_sfnt_off0000e85a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE85A 10712 bytes
SHA-256: 4f3fd07dbe6fcff53707e9d3b1efd54139f980f1b12e191ca337a6981828a7f3