Malicious PDF — malware analysis report

Static analysis result for SHA-256 efef2593a62033b4…

MALICIOUS

PDF

73.4 KB Created: 2021-09-11 23:57:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: f3013ba4d58ae643582cc6dfb926a388 SHA-1: 71400ee1f8d448c191fcd87f2a70119ea5423456 SHA-256: efef2593a62033b4e05905b172957abd2929459b79e803b235ef92c02020f1d4
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to redirect users, and ClamAV detection confirms it as a phishing trojan. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://pistant.ru/uplcv?utm_term=mini+militia+mini+malaysia PDF link annotation
    • http://xn--eyt274i.com/upload/files/nipijawaju.pdfIn PDF document text
    • https://olgunbey.com/upload/ckfinder/files/13908262028.pdfIn PDF document text
    • http://josquin-capella.de/download/jovewafemimunodumi.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/19155058577.pdfIn PDF document text
    • http://camelliafb.com/uploads/files/202109081405265488.pdfIn PDF document text
    • https://www.frontiermea.com/sites/all/libraries/ckfinder/userfiles/files/84839104547.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/95259154272.pdfIn PDF document text
    • http://tumwebthailand.com/ckfinder/userfiles/files/gemotaz.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134812d21b53---25315072549.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/85017674839.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c10c958abb---pipuxilidibusumilimamifes.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/qhun0ls6jqfanihis2ibtggc0d/ramuwa.pdfIn PDF document text
    • http://www.biogreeno.com/cms/ckfinder/userfiles/files/fegivuxujowa.pdfIn PDF document text
    • http://cl-metalparts.com/d/files/56870740006.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/16342509254.pdfIn PDF document text
    • http://odessawa.com/userfiles/file/boboponofafamo.pdfIn PDF document text
    • http://studiotecnicobergamaschi.it/userfiles/files/nipojonitabokaliv.pdfIn PDF document text
    • https://pchome.uzai.ca/upload/files/maluna.pdfIn PDF document text
    • http://matraholding.hu/images/userfiles/files/nuzuwuxukusifidu.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/40203759915.pdfIn PDF document text
    • http://pronobile.de/catalog/file/xoluvimepuwawevomode.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_off0000be24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE24 10024 bytes
SHA-256: 8d1bcd179fb1aca10eac0d5cacd838d06ef1bedc97cc0c9f97e066b30c978268
font_01_sfnt_off0000d449.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD449 17088 bytes
SHA-256: 31d775cb52c3df2e47939f89cfddc110fd4f6fc99ed62d3424e3dc062811eb08
font_02_sfnt_off000100b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1