Malicious PDF — malware analysis report

Static analysis result for SHA-256 101ca6164bae9fc9…

MALICIOUS

PDF

80.1 KB Created: 2021-09-15 17:50:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 94e868257a3818cfca57563cb97dfe3c SHA-1: 0709b2a99d6671e1b50d5b2d3ae626ef48dc79ed SHA-256: 101ca6164bae9fc9ce63e495894c3b1fba51718b8c12d5c6f6c6edf61fbe40c1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple domains, many of which are hosted on disposable infrastructure, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support the conclusion that this document is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://lachina.cn/upload/file/3099284015.pdf In PDF document text
    • https://cet.sk/res/file/vovevukagukojasopurerol.pdfIn PDF document text
    • https://makiriaszto.hu/ckfinder/userfiles/files/tomenufosujunebij.pdfIn PDF document text
    • https://euroialinsol.ro/userfiles/file/24017674744.pdfIn PDF document text
    • http://drapa-technika.cz/UserFiles/File/19956426940.pdfIn PDF document text
    • http://aktifithalat.com/resimlerfiles/lijefaxetonarosoloxi.pdfIn PDF document text
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/57013037569.pdfIn PDF document text
    • http://www.centrosanmarco.eu/img/news/files/97403921885.pdfIn PDF document text
    • http://affordableadobe.com/ckfinder/userfiles/files/tuluzenarizitaro.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/18430837075.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/161358242a8cb4---88042973924.pdfIn PDF document text
    • http://asremajazi.com/uploads/files/zukupinima.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/kivobodalin.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/56697613686.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/f5efc4a3ae1494f851fce410b5bc1739/65948732502.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/bukekoridilosadizizaga.pdfIn PDF document text
    • http://glampingcaravan.com/userfiles/file/20210905095655.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/d0096d2bb7b7da1ea30621a98e26a708/24427586619.pdfIn PDF document text
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/35557588864.pdfIn PDF document text
    • http://metall-press.ru/files/wuxezirifilugaron.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133540b57ce9---9470115329.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=fifa+20+download+obb+filePDF 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_off0000d554.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD554 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED6B 10424 bytes
SHA-256: 168711d2fb2e66d60fd477efeb4f9db04685cec02804c2e814e15b7740f61d86
font_02_sfnt_off0001052a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1052A 17568 bytes
SHA-256: fc048a8d71674443a1feddbe93e0df7b1094137070480e13acb92a9a718ca93b