Malicious PDF — malware analysis report

Static analysis result for SHA-256 43a5ddf806f129de…

MALICIOUS

PDF

69.9 KB Created: 2021-09-15 22:24:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f673a38eada6715a4dd8fdf51519006a SHA-1: 78620741098c496864557eb1f66ada01ed845267 SHA-256: 43a5ddf806f129de58eab1713f475a7f9e6d731557f48798acad74b63fcd6208
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and points to compromised CMS upload storage, suggesting it's designed to redirect users to potentially malicious content. The presence of embedded URLs further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://coretry.ru/uplcv?utm_term=outlook+login+password+reset PDF link annotation
    • http://classicalgardenfountains.com/uplds/file/71458640723.pdfIn PDF document text
    • https://tasteadmin.com/ckfinder/core/connector/php/custom/wysi_uploads/files/dapidaruri.pdfIn PDF document text
    • https://acavacecio.it/userfiles/files/60803591646.pdfIn PDF document text
    • https://kohphanganhotelandtour.com/userfiles/file/1557260355.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/69078064753.pdfIn PDF document text
    • https://tedesco.pl/userfiles/file/wedibipulolejutiz.pdfIn PDF document text
    • http://school15-tyumen.ru/f/89551919382.pdfIn PDF document text
    • http://teplo76.ru/uploads/file/zifenezivumus.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/4e5a7071bdd25c4bbf4f2d0625ae6593/56684049698.pdfIn PDF document text
    • http://vivaibonomo.it/userfiles/files/somulipumu.pdfIn PDF document text
    • https://soi.icami.mx/ckfinder/userfiles/files/jomowovefofo.pdfIn PDF document text
    • http://superfishinglewood.com/uploads/files/83153015435.pdfIn PDF document text
    • http://divodizain.ru/ckfinder/userfiles/files/15946600961.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/turuva.pdfIn PDF document text
    • http://evaemlak.com/userfiles/file///94421311112.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3c050bb74---guxiropamorapos.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/aafcb75e83163460ddb3fee29618dedb/wibufumijib.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/43685118368.pdfIn PDF document text
    • https://www.gico.ge/ckfinder/userfiles/files/jegazeraputemabixixudow.pdfIn PDF document text
    • https://maytinhdalat.vn/images/uploads/files/10416778616.pdfIn PDF document text
    • http://irvine.songhakbbq.com/uploads/files/38663878245.pdfIn PDF document text
    • http://www.fred-robin.com/ckfinder/userfiles/files/10273742251.pdfIn PDF document text
    • http://perilatomsk.ru/ckfinder/userfiles/files/mimujelezukuwanab.pdfIn PDF document text
    • http://gatewayhotelbangkok.com/upfile_hotel/files/nawaxebipipiboponadosuno.pdfIn PDF document text
    • http://sake2metustin.com/uploads/files/torerud.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109090248589337.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://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_off0000b47c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB47C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC93 10872 bytes
SHA-256: fd950360ac5e7d9ba7e12d767649b4f4ae0f401197a4a1a0a64ddef408f8df24
font_02_sfnt_off0000e5bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5BC 14472 bytes
SHA-256: c150961f376fc148f9373bba30b0891c2f2314d5f570a656ff6cd4948ba7ae52