Malicious PDF — malware analysis report

Static analysis result for SHA-256 799a3b5c319b6331…

MALICIOUS

PDF

71.6 KB Created: 2021-04-10 14:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: e57ef4db76e240bf868e82491cf84aa2 SHA-1: a6b9dde6cb32566d32382247b83f35a4ff4528c1 SHA-256: 799a3b5c319b63315b6753e76580e13126d0cd6682d4d54bedaed298b1341bb1
134 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a phishing or trojan threat. The presence of numerous external URIs, including a link farm on disposable hosting, suggests an attempt to redirect users to malicious content. The 'SE_DOWNLOAD_BUTTON' heuristic further supports the lure-based attack pattern, aiming to trick users into downloading a payload.

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://www.uts.cw/sites/default/files/webform/89737617204.pdf In PDF document text
    • https://www.jwico.com/sites/default/files/webform/xojisipet.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/jilagofuzepev.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/80628544521.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/dufadurelabakugozuku.pdfIn PDF document text
    • https://europa-ts.ru/sites/default/files/webform/6529842099.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/veser.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/14219433733.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/larigujumikanezazezogiwi.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/vogoledifekotukedadawen.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/zatepatepekaberemosigedix.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/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=coordinate+grid+picture+worksheets+fPDF link annotation
    • https://community.princeton.edu/system/files/webform/wijudabopijobomoxusosul.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/86626084736.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/43157208480.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/83703622856.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_off0000da80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA80 5448 bytes
SHA-256: 0964bf200435299c114b6d7efed9f6cbb9d95698815545ac0e909bccff9b29c9
font_01_sfnt_off0000ed19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED19 10656 bytes
SHA-256: 05452289c86a98781cf3b2da17a553a0181313690b8f8501c9c39707fa8719b0