Malicious PDF — malware analysis report

Static analysis result for SHA-256 733ec28883c80c3d…

MALICIOUS

PDF

69.9 KB Created: 2021-10-03 14:23:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e94872be690d576e7520dc8eb396787f SHA-1: 352ba368b82f2f2f0287fecc60cbf940aee15c57 SHA-256: 733ec28883c80c3d65dffd9a359fbebebb5b9f92e161a313aaf239996e60002c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged as malicious by both ML classification and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous embedded URLs, many pointing to potentially disposable domains, suggests a phishing or credential harvesting attempt. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic further supports this, indicating the PDF is designed to host multiple links on low-reputation domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://chrisdepanneservices.com/Sites/cds/files/zaxeko.pdf In PDF document text
    • https://insolite.lu/img/userfiles/files/2454844396.pdfIn PDF document text
    • https://testpensija.bankai.lv/ckfinder/userfiles/files/49369819478.pdfIn PDF document text
    • http://suachuamaydemtien.biz/userfiles/file/waditef.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/8266155877.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/45451501416.pdfIn PDF document text
    • http://briztravel.com/upload/files/zumojumopafasinesirix.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/39136456123.pdfIn PDF document text
    • https://denizlihorozu.com/resimler/files/80464335092.pdfIn PDF document text
    • http://fd-health.com/upload/ckeditor/files/saradapogenetofubazatowu.pdfIn PDF document text
    • http://xn--42-jlclgg6a3e.xn--p1ai/userfiles/file/xifonemeror.pdfIn PDF document text
    • https://sua.vn/uploads/userfiles/file/vokujosivugutapuram.pdfIn PDF document text
    • http://vlajamo.cz/images/file/95877664885.pdfIn PDF document text
    • https://deycaterers.com/ckfinder/userfiles/files/60546367404.pdfIn PDF document text
    • https://creteservices.com/FCKeditor/userimages/file/waxumasixibirasef.pdfIn PDF document text
    • https://polresseluma.com/assets/ckfinder/core/connector/php/uploads/files/74339912676.pdfIn PDF document text
    • http://yanartekstil.com/firma/files/kebufobanegadu.pdfIn PDF document text
    • http://dichvu12h.net/userfiles/file/zilavita.pdfIn PDF document text
    • https://pustelnik-budownictwo.pl/ckfinder/userfiles/files/61162559348.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/medapujimexo.pdfIn PDF document text
    • https://pharmawell.eu/ckfinder/userfiles/files/kinesoluwirifoxikezisoji.pdfIn PDF document text
    • https://mar3ol.com/Files/files/bejojuvumegewuzaxoburoto.pdfIn PDF document text
    • https://hediyelikhanem.com/calisma2/files/uploads/27701650186.pdfIn PDF document text
    • http://theclubburger.com/uploads/files/sotupamefijiza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=sympathy+message+for+coworker+loss+of+motherPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b213.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB213 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA25 14976 bytes
SHA-256: 9b503fb1aeaeba737a46ef041de8ec9787230d8411904338c90e1d40a83d23eb
font_02_sfnt_off0000ef8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF8C 11096 bytes
SHA-256: 0598bc00296b4a033a0e8add0e5a145d2884c633c5a5ebce6f67b624204a0043