Malicious PDF — malware analysis report

Static analysis result for SHA-256 f36cde3a83450217…

MALICIOUS

PDF

82.0 KB Created: 2021-09-14 04:15:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 71d3628d533b4611cc1c3756290d80e9 SHA-1: 60073ac6ea8620d89fd9e897af4fa88e2039146a SHA-256: f36cde3a83450217079e7c2f7715776df9fd57ea6ec8ebdf9a03f47ea79f7403
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains, suggesting a link farm or content distribution network. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic firing confirms this, indicating a non-clustered link farm on disposable hosting. While no scripts were explicitly extracted, the nature of the embedded URLs and the ML classifier's high confidence score suggest a malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae74e0c18e---suteli.pdf In PDF document text
    • https://karaari.leaddeehub.com/userfiles/files/dinorinugi.pdfIn PDF document text
    • http://keramann.ru/uploads/files/20688651313.pdfIn PDF document text
    • http://webcertain.asia/contentupload/fckeditorUploads/organization_/file/79879717548.pdfIn PDF document text
    • http://viethanit.vn/hinhanh/file/26914431213.pdfIn PDF document text
    • https://alemarferries.alemarsnp.gr/ckfinder/userfiles/files/givem.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/zavewesetusetudujet.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/diputedidabururedupejujum.pdfIn PDF document text
    • http://msiutilities.biz/documents/fuvose.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/xodana.pdfIn PDF document text
    • http://lamardaegu.com/upfile/user/file/vuliwetenijedimatodoru.pdfIn PDF document text
    • https://people11people.com/uploads/File/misojepifalewutujobo.pdfIn PDF document text
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/74397651560.pdfIn PDF document text
    • http://safedoorsystems.com/cmsimages/file/20371252084.pdfIn PDF document text
    • http://transgusto.ch/userfiles/file/jufavobepudob.pdfIn PDF document text
    • http://chandigarhdatarecovery.com/files/file/vajixisugiferefepedus.pdfIn PDF document text
    • http://aviafond.ru/userfiles/file/84189906910.pdfIn PDF document text
    • https://congnghieptauthuyvietnam.vn/upload/files/59065780879.pdfIn PDF document text
    • https://fajndoktor.cz/images/file/files/61531651062.pdfIn PDF document text
    • http://kcpsystem.com/userData/board/file/22807528465.pdfIn PDF document text
    • https://hattshopping.com/admin/assets/images/ckfiles/19105617283.pdfIn PDF document text
    • http://metalzilemboeventi.com/userfiles/files/92508793633.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/walaretofivapufupokegafuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=2k19+psp+game+downloadPDF 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_off0000db04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB04 18116 bytes
SHA-256: cc2e4e65e3721b1c7f15b98cab7fa9c48ed836e1a261ff0ff335f3cdf7ed5d08
font_01_sfnt_off000109fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109FE 10864 bytes
SHA-256: 5c33b6ffc724c57f6604294e18caaf96260aecc9422bf482b69a42117465c76b
font_02_sfnt_off0001230b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1230B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1