Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1a51eca81d9bcfe…

MALICIOUS

PDF

81.0 KB Created: 2021-06-23 06:50:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 26539f99d5552e585b0c57c56db51864 SHA-1: 9d335c2f058605b594e1b936bbe0a9a37b9a024e SHA-256: e1a51eca81d9bcfeea7ee05e0cdcd2fc83cc0dc669f9e51998915e06ad7596cf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised websites and disposable hosting domains. The embedded URLs, such as http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/3937a23154debf20b238f490995a4dba/kupizekinabu.pdf, are likely used to distribute further malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a2891b80c4d---rulizifadusaxunebiv.pdf In PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/8ea23a0eccb4ca4f894b20db28ce2265/tabetivesojiw.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/lfjl1c86ks41l9hq30mdm0d3og/fezafovor.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/munipenopuja.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/zesekofusu.pdfIn PDF document text
    • http://kistours.hu/userfiles/file/dozuj.pdfIn PDF document text
    • http://johnmichaelharrisonlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xasovowe.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160b7f696b756a---fidaxugorezizamokisiratin.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/gc7l9op0lshi7mp60s3s4gdlho/nigaroxijorepeka.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/9f5d4372d7122b85690b9e375cc6b2c4/26956261246.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/3148e91f547ddf57a0273b0915dd02fa/vafupo.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160ab96fe097bd---32194097597.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/3937a23154debf20b238f490995a4dba/kupizekinabu.pdfIn PDF document text
    • https://zionapostolicministries.org/uploads/file/80380424985.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/tisfvda8sts277udiqriipiutg/wenabidawegob.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/53259993551.pdfIn PDF document text
    • http://ayurveda-shiatsu-nice.com/upload/files/kogevejizumurotilezadire.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=naked+and+afraid+completely+uncensoredPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fc77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC77 5436 bytes
SHA-256: b144c0725c15324ec2510e8d5681555a1297e493e75b35d2e674aa45bc9f3375
font_01_sfnt_off00010ef7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF7 11340 bytes
SHA-256: 08039368fa99beb2fd99aa79a38ac387cf687805c335baf92edab5ad52eea183