Malicious PDF — malware analysis report

Static analysis result for SHA-256 8374fab949998857…

MALICIOUS

PDF

88.8 KB Created: 2021-08-14 02:11:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7a02d385e5350685fc00b1b6647c6c51 SHA-1: 31b3e266d5f0402a6dc0f3aee8b6b01cdfb12fc4 SHA-256: 8374fab949998857cb7b2d7a23445d961dbee03789cfac66a5954d91766bc0f6
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a vessel for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://briljant-maleri.se/UserFiles/files/27139846669.pdf In PDF document text
    • http://altelaw.com/uploads/image/file/zodemulimapupekabiru.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d5efb0dfb---kewotewalarexatukugetap.pdfIn PDF document text
    • https://itchanoi.vn/uploads/news_file/maloxofisixarevatavopoxe.pdfIn PDF document text
    • http://riversreunion.org/clients/8699/File/bejokuwazomazofi.pdfIn PDF document text
    • http://vdavloeren.be/userfiles/files/20588816236.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/cb0d734465085a13138879397bcee776/85368230389.pdfIn PDF document text
    • http://tanphatinst.com/vietkiendo/upload/file/28557072151.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16074d114077f3---92168578007.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/zibadusefaru.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/jekososifipaxalugigis.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/241c867ae18225f5adcdfad482860a7e/palinomevikuvixuketewalop.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/safuvamesebaxuf.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/55860366953.pdfIn PDF document text
    • http://djarkitek.com/temp/vinney/HTML/userfiles/file/bujurifumavuxuj.pdfIn PDF document text
    • http://tcihk.com/userfiles/tolapixiwotafi.pdfIn PDF document text
    • https://clickkedai.com/userfiles/file/39709805574.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/migifedozutewevis.pdfIn PDF document text
    • https://artlabjo.com/userfiles/file/23512175244.pdfIn PDF document text
    • http://papinchess.ru/userfiles/file/59688317206.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/welutuv.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ea2551f7a1---29937511135.pdfIn PDF document text
    • http://lineshare.net/upload/files/20210628102733.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+build+a+strong+popsicle+stick+truss+bridge+with+trianglesPDF 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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B6 16984 bytes
SHA-256: 1dfa2f938f3509f5d79ce80f06bbd233b4859665b6d72501709ebbd2946bad78
font_01_sfnt_off00012299.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12299 11200 bytes
SHA-256: 2e7d736df8f9dab990d93cf3761856089b2343ef36db8b891ca3e00bdf9b42e1
font_02_sfnt_off00013c5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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