Malicious PDF — malware analysis report

Static analysis result for SHA-256 b74dc7b898c31ba3…

MALICIOUS

PDF

68.7 KB Created: 2021-09-24 19:05:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cd9f384e6b22ddfbb69d24dcc0fb255f SHA-1: 3f62c35751c90cc9a7da8a9c8c436343ce0e61f8 SHA-256: b74dc7b898c31ba390fcdc6bbfef9bb4854930c481a0842b7826572f35560fef
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous external URLs, some of which point to compromised WordPress upload directories. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://soluzionebenessere.eu/userfiles/files/nataxutigokitegudop.pdf In PDF document text
    • http://re-media.ru/foto/ck/files/59860466324.pdfIn PDF document text
    • https://apgr.eu/UserFiles/file/39542967760.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/qpg0fs07sn9qp7u4ek5savbrn2/8289339169.pdfIn PDF document text
    • http://alanaf.ru/userfiles/files/87379255412.pdfIn PDF document text
    • http://urgentcarepb.net/userfiles/file/14996673936.pdfIn PDF document text
    • http://okna-stv.ru/userfiles/files/75010891813.pdfIn PDF document text
    • http://vitacanes.com/uploads/files/21862234679.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/womusizanutafa.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/8891949619.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa2dfd10dc---3479647139.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/60832855111.pdfIn PDF document text
    • http://www.s-prom.si/fileupload/file/rupivududadepebavu.pdfIn PDF document text
    • http://insfilings.com/skyzone_classic/upload/files/bepomomavi.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/151930fd8b0e06d50603fb853bd819ff/91766376834.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139357c179e9---92232840919.pdfIn PDF document text
    • https://betsin.org/userfiles/files/49150160639.pdfIn PDF document text
    • https://menu2uplus.com/images/file/86524265090.pdfIn PDF document text
    • https://nurea.se/currency/userfiles/file/gapukuvetixevolojezasuf.pdfIn PDF document text
    • http://khonggianmang.com/upload/files/papavekirijedopimawi.pdfIn PDF document text
    • http://mrpennarak.com/user_file/file/saziba.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=rope+hero+rise+of+the+machines+mod+apkPDF 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_off0000acfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACFE 15468 bytes
SHA-256: 620bda3e5cb43b07322209ddc23c534ffdaf4ffa9d23e36f7f58026a1f2b47c3
font_01_sfnt_off0000d42f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD42F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC46 10976 bytes
SHA-256: 4cdb67ae0d538f109c08ea16758086f3caf32bb34228fc60b17126d65b73f4ae