Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9e56e31b37a19f5…

MALICIOUS

PDF

69.7 KB Created: 2021-09-26 12:14:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: eced1fa5974b5d171163aeb9da2b0f99 SHA-1: d20efc2e7036ba09f468d4bc121dd058f66f4ac1 SHA-256: a9e56e31b37a19f5e866c500b50891e1eb0be7631edbea85706bd11dd747b012
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to disposable domains, suggesting a link farm or phishing infrastructure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to host many links on potentially untrusted or temporary hosting. While no scripts were explicitly extracted, the nature of PDF malware often involves exploiting vulnerabilities or redirecting users to malicious sites, aligning with the observed URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://irlanc.ru/uplcv?utm_term=blackboard+learn+app+for+android PDF link annotation
    • http://apmnir.ro/fckfiles/file/gasabesevogom.pdfIn PDF document text
    • http://budaikepkeret.hu/uploads/file/81905590419.pdfIn PDF document text
    • https://cam-ceeds.org/ckfinder/userfiles/files/33114091676.pdfIn PDF document text
    • http://www.ciesol.es/ckfinder/userfiles/files/64880979774.pdfIn PDF document text
    • http://bxbrdh.marketsearching.com/upload/files/bopek.pdfIn PDF document text
    • http://greenld.com/userfiles/70828747869.pdfIn PDF document text
    • http://gdlejia.com/uploadfile/files/20210905_014423.pdfIn PDF document text
    • http://xfswchem.com/upload/files/dadujewimek.pdfIn PDF document text
    • https://coopinproject.eu/ckfinder/userfiles/files/fedijagujukebosudedat.pdfIn PDF document text
    • http://blgjad.com/upload/files/kujujamamijifoga.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419e6f5106e---33133869462.pdfIn PDF document text
    • http://taigesw.com/upload/files/voluwoluze.pdfIn PDF document text
    • http://tunesistudio.eu/userfiles/files/sepikuxezejup.pdfIn PDF document text
    • http://meghdoothsuzuki.com/uploads/63574204420.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/94910179023.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/30635469414.pdfIn PDF document text
    • http://ancient-theater.gr/media/file/96587792905.pdfIn PDF document text
    • https://bawauang.com/contents/files/xoputukurupiwu.pdfIn PDF document text
    • http://reguitti-engineering.it/userfiles/files/22326152800.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/vikati.pdfIn PDF document text
    • https://faguaflowers.com/images/admin/file/jidemevebomosanofo.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/lijosifunisave.pdfIn PDF document text
    • http://les-dvorik.ru/userfiles/file/baxugogotomuxebigonifu.pdfIn PDF document text
    • http://wittlich-luexem.de/userfiles/file/98293188711.pdfIn PDF document text
    • http://altadirezione-consulting.it/userfiles/files/49484271215.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_off0000b1f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA07 14816 bytes
SHA-256: 40bf3d8c76c34e59c0d7fb731596ac51f576876c8d251bc33ed4fffa8ba61745
font_02_sfnt_off0000eef3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF3 10632 bytes
SHA-256: 459b4ef91eab5f5d6a4a17e5260ba8bc4978806e6de61655ffded0118d456707