Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4695cb474cacda1…

MALICIOUS

PDF

83.4 KB Created: 2021-10-07 07:26:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: fa94dee8bebd4dab94b6305abc00742c SHA-1: e8b8af4032ff0444299bd07b945c1ecb14e7e5f2 SHA-256: f4695cb474cacda17cb3c6b9338ca8e282e73a646a0bb0d990c7fc49b9ca5720
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, many of which are hosted on compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://mextro.de/upload/files/2915150636.pdf In PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/nekoko.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd3fa353dd---fonapawefofa.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/94233704299.pdfIn PDF document text
    • http://grabnerestriche.at/9451964959.pdfIn PDF document text
    • http://ohadalegistrocbarter.com/ckeditor/uploads/files/36857288245.pdfIn PDF document text
    • https://slezanie.eu/userfiles/file/wapeguvavemoxepifazarudiz.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109062224015421.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/1urik60smtp4an7p6hutmcpuer/niwun.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/kugenazala.pdfIn PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/nilenag.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133106dd67c4---69401911801.pdfIn PDF document text
    • http://full814.com/upload/files/13616673344.pdfIn PDF document text
    • http://lamekatus.com/uploads/ckeditor/files/makomejagi.pdfIn PDF document text
    • https://doan295doson.vn/namthuan/images/news/files/fojixadebavidit.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153a1c797ac5---sexudinaf.pdfIn PDF document text
    • https://olterus.net/contents/files/popakofadike.pdfIn PDF document text
    • http://yilbasipromosyonu.com/userfiles/file/61248358453.pdfIn PDF document text
    • http://aktien-analyse.de/images/File/3967679333.pdfIn PDF document text
    • https://ski-valloire.com/ckfinder/userfiles/files/muwuzapebuxuradita.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/demexomopagimava.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161403329de3f7---nelow.pdfIn PDF document text
    • http://master-stroi76.ru/userfiles/file/31957736441.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/lenoxud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=best+airlines+to+flyPDF 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_off0000e135.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE135 18272 bytes
SHA-256: 3eba0d853405759a9e47bb63b3b6302214a3dfa1773f75cbe946d9a5d8428182
font_01_sfnt_off000110c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128DF 10376 bytes
SHA-256: 30c6c259d589ea6106360fe87cd72bb39eafa2441545846684c2ffc64cf61f56