Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4fa18c220136535…

MALICIOUS

PDF

80.2 KB Created: 2021-09-17 14:27:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e22ce49991849cf4031e327b6d688ba9 SHA-1: 4f1c50a643c918d52bcdd3192282cd27465a28ce SHA-256: c4fa18c22013653503b28a906d23e80fd1cd17e66da68ae80303baf9c8aefd9b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous external links, including one pointing to a compromised WordPress upload directory and another to a URL with a 'download free call apk' UTM term, suggesting a lure for users to download potentially malicious software. The document body is heavily obfuscated, preventing a clear understanding of its immediate purpose beyond linking to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://coretry.ru/uplcv?utm_term=download+free+call+apk PDF link annotation
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142500be9f55---devanabidogimawet.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1ea68524e---livipijusi.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/58945546636.pdfIn PDF document text
    • https://network-italia.it/file/94433283612.pdfIn PDF document text
    • https://yasacompany.com/upload/files/12005990992.pdfIn PDF document text
    • https://stichtingech.org/ckfinder/userfiles/files/92190423409.pdfIn PDF document text
    • https://mamo-tato.ro/userfiles/file/2928873792.pdfIn PDF document text
    • http://aunay-sous-auneau.fr/ckfinder/userfiles/files/51829267232.pdfIn PDF document text
    • http://agisinfo.ru/uploads/content/files/kurepagumikogixakizajul.pdfIn PDF document text
    • http://krr-nfe.com/suratnfe/UserFiles/File/5092913550.pdfIn PDF document text
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/91978476673.pdfIn PDF document text
    • http://xedaphcm.com/luutru/files/polobuvigidedokumot.pdfIn PDF document text
    • https://albizy.com/ckfinder/userfiles/files/jumagamokimugubogo.pdfIn PDF document text
    • http://ahzycw.com/upload_fck/file/2021-9-15/20210915191639731263.pdfIn PDF document text
    • http://moristas.com/userfiles/files/texixenuson.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/gowixapefuvigu.pdfIn PDF document text
    • http://retrievers.su/ckfinder/userfiles/files/xasatelesodudafo.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/77919155416.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/kebafivufupubuwep.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f52de5c7f4---ruvoboto.pdfIn PDF document text
    • https://digireg.at/upload/58892719278.pdfIn PDF document text
    • https://unimedbelem.com.br/painel_template/assets/global/plugins/ckfinder/userfilesfiles/80868532343.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_off0000d5fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5FA 10432 bytes
SHA-256: da909d5385184e77945ae8b6345f3309a5ac90054255ece27d70a72fd7a24f10
font_01_sfnt_off0000edca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDCA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DC 17664 bytes
SHA-256: 2c3bba89fadbda38a19c72b18904202a06b52333127e8b1cb5ecac23d9a17439