Malicious PDF — malware analysis report

Static analysis result for SHA-256 13acfadeba04d961…

MALICIOUS

PDF

83.2 KB Created: 2021-08-22 00:07:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 644bbacfe62116b959e890b8cf0ce000 SHA-1: a23057ee4d18a089cd415dd69a11edac8c552b0d SHA-256: 13acfadeba04d9619e86f4733a1fae85d0ba81f64cb2725f041559a3d4f4e1b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to potentially compromised or disposable hosting sites, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to exploit users via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://chcial.ru/uplcv?utm_term=numerical+methods+for+engineers+7th+pdf PDF link annotation
    • http://vanlysecurity.vn/vanly/album/files/86138795021.pdfIn PDF document text
    • http://szsahsh.com/uploads/files/fimebiwegeboge.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/ralemudo.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608952c2e3f6a---9210834713.pdfIn PDF document text
    • https://hyundaia.ru/userfiles/file/84264902436.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611e86b352d4a---wabiwevasidoj.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/23366941419.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/wixorexiposufakaxilakit.pdfIn PDF document text
    • http://galgalesh.com/userfiles/file/bijawuluni.pdfIn PDF document text
    • http://www.buildingmalawi.com/images/uploaded/documents/buxivokominawupifesazup.pdfIn PDF document text
    • https://vestol.bg/files/file/48861668528.pdfIn PDF document text
    • http://bertoniamministrazione.it/bertoni/public/file/tidefuwefovax.pdfIn PDF document text
    • http://www.ruben.pl/ckfinder/userfiles/files/50721129000.pdfIn PDF document text
    • https://lecachet.fr/docs/files/26549356762.pdfIn PDF document text
    • https://fereshtegan.net/basefile/fereshtegannet/files/35073484046.pdfIn PDF document text
    • https://smartmedia.ro/app/webroot/files/userfiles/files/pefojugomajilufusevufibe.pdfIn PDF document text
    • https://slezanie.eu/userfiles/file/7918471201.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/segikagabazufa.pdfIn PDF document text
    • http://rszm88.com/upfolder/e/files/20210802102428.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8147b1d6a---88746037750.pdfIn PDF document text
    • https://mayurherbal.com/userfiles/file/boduxuda.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160f751db25ac5---54160902783.pdfIn PDF document text
    • https://opuntia.eu/wp-content/plugins/super-forms/uploads/php/files/5c673e2d1f74a3476c3be994efc4d61e/julunibafibiderulivuweg.pdfIn PDF document text
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/rurolimotoz.pdfIn PDF document text
    • 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_off0000df82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF82 17604 bytes
SHA-256: 9e6f2fcd4444939fa515d61afb9d72c23e56c7dda48d2c9d4cb9b5d485a94a86
font_01_sfnt_off00010c92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C92 11192 bytes
SHA-256: 7786b3d45291755a274103ed7211ca1c10e191175d651d0138fcab181be044ce
font_02_sfnt_off00012669.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12669 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1