Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4b8fcfc092e4b0b…

MALICIOUS

PDF

78.8 KB Created: 2021-04-09 05:46:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 7d43bf7e8e9160c8e1838a35134315f8 SHA-1: c40f32dffba503164e2465f026b82fd16ebf4a22 SHA-256: b4b8fcfc092e4b0b9481a76c29b768d4158e8c42ac5196f03c699b3572904bc1
134 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs and is flagged by ClamAV as Pdf.Phishing.Trojan. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a link farm on disposable hosting, suggesting a phishing or scam attempt. While no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/87762274679.pdf In 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://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/bekam.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/woximinel.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/43963154407.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/kepasibadugemefobovabo.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/8025899801.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/masugikiretige.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/noranixuguwetepefosobad.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/subeditanutojodojewogize.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/59680287402.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/47545977947.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/fadubapep.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/vogelunejubujapezidugave.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/tajiwugebewozebukak.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/S30rS-6n6vg/uplcv?utm_term=kcpe+answer+sheet+sample+pdfPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/lezedatabamivija.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/53252105934.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/fanonexujezurexuli.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/xakunowegetudirojevogejiw.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_off0000dedf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEDF 4160 bytes
SHA-256: a87a80109964d2e82ec550568e12967fad0e9f9380e6f0c7b41882603e201df0
font_01_sfnt_off0000ed91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED91 5456 bytes
SHA-256: 4c4981cf0bb5d1505f8be5859135e40cdac8a407ea82a9412639aa35ec2ef59f
font_02_sfnt_off0001000f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1000F 14044 bytes
SHA-256: faa90ead009d6f7a0fbd6a34962418b92bf2f12d181a3d729080cda1c9861913