Malicious PDF — malware analysis report

Static analysis result for SHA-256 fbb387ae737f548b…

MALICIOUS

PDF

83.8 KB Created: 2021-09-11 18:02:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2f6f3097e3a0f0c9e04a1a593ef41329 SHA-1: daf9b07cbc48b5d4fdbe660c401c9bd4e75e94bb SHA-256: fbb387ae737f548bd60fcf5544f97fd24ce718186f0f07fb2a96f4ff41aa4e0a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm used to distribute malicious content or phish for credentials. While no scripts were directly extracted, the PDF structure and heuristic firings indicate it's designed to redirect users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://okna-kurska.ru/page_edit/_samples/userfiles/files/kikazisurobizopubuxuvoj.pdf In PDF document text
    • https://gujaratisamajparis.org/upload/files/49822954725.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/1af56e7a54170fa470f25e9e2383dd2e/26128084929.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/72136906236.pdfIn PDF document text
    • http://videocycling.info/files/file/77205073771.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130e95cd5ac2---wesosafazomobaduz.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/romojijamekusisalujinixa.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202109100855215492.pdfIn PDF document text
    • https://yellowstonewildlife.com/97319807239.pdfIn PDF document text
    • http://8njl.com/userfiles/files/xegedawexodam.pdfIn PDF document text
    • https://bevasilicones.in/userfiles/file/73143130644.pdfIn PDF document text
    • http://donauwell.at/userfiles/file/74888104797.pdfIn PDF document text
    • https://permargi.com/files/galeria/files/11637769404.pdfIn PDF document text
    • http://wizclub.net/upload/userfiles/file/dilapubufinimugukevej.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/xuxegijere.pdfIn PDF document text
    • https://vico-inmobiliaria.com/ckfinder/userfiles/files/52713430670.pdfIn PDF document text
    • https://srldirect.com/ckfinder/userfiles/files/7354056486.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/14990040526.pdfIn PDF document text
    • https://duongthuy.net/userfiles/file/28884882122.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613b785bcb2cb---rixekupapojumuko.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16132671992589---zejotofoziwu.pdfIn PDF document text
    • http://islandpointfl.com/userimages/sejimofagever.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+recover+deleted+system+files+on+androidPDF 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_off0000e07c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE07C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f88e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF88E 18484 bytes
SHA-256: ee1de972652c352a217ef16f91861a0c0fb12aed56691686d876f58c3a5270f8
font_02_sfnt_off000127f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127F5 10892 bytes
SHA-256: ae399f8dc9b77839f2ef8d95919da7e8528c7fffd467420a9a3595c3c21d8bef