Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f820440642123cd…

MALICIOUS

PDF

80.9 KB Created: 2021-09-15 22:30:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d9e52b97f2b43dd4e101c82cc690ec83 SHA-1: 5098dcb8db4ad7f6b5b17d8c5d47e692894dcb24 SHA-256: 5f820440642123cd889caf7be5b392ed720a8ae1797454227b55d1a186b4dc4b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external sites, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests these are used in a link farm designed to obscure the true destination. While no scripts were explicitly extracted, the presence of embedded URIs and the nature of the heuristics point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://vhktn.at/images/content/files/52343324591.pdf In PDF document text
    • http://app0.linkeo.it/ckfinder/userfiles/files/87520026528.pdfIn PDF document text
    • http://itps-group.com/uploadfiles/file/wenivorikikuvepa.pdfIn PDF document text
    • http://buffagiuseppeinfissi.com/userfiles/files/biwojoxebipa.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/niduzaxotetigafuzawasizod.pdfIn PDF document text
    • http://vetsnab32.ru/userfiles/file/36798618446.pdfIn PDF document text
    • https://dalba.net/other_files/File/lizoxazukixedab.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/20648851348.pdfIn PDF document text
    • https://dreptultau.hotnews.md/upload/userfiles/files/xixawubujupegumasip.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/xejaroloraxixikov.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/zovapepuf.pdfIn PDF document text
    • https://trouver-une-ssii.com/img/pics/files/nuzabojo.pdfIn PDF document text
    • http://otohondamientay.com/upload/files/23056066265.pdfIn PDF document text
    • http://csc021.com/userfiles/file/20210912071140_nxg8mn.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/jajesozisaxunos.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/22976160025.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/1b18b87462c0a03f1aa84ce6cb55297d/retivurawijej.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/p1hoj8f0oblbcfpi77n1vvqis8/23072452935.pdfIn PDF document text
    • https://tedvandergulik.nl/userimages/file/luzajewuterot.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/semolalix.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/ruvawusotatawiloxev.pdfIn PDF document text
    • http://goldmustang.com/files/files/96721163538.pdfIn PDF document text
    • http://kowalstwwo.pl/public/cms/images/file/6647510834.pdfIn PDF document text
    • https://www.supremecaravans.com.au/application/third_party/ckfinder/userfiles/files/34071750763.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/99635145640.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=sanam+teri+kasam+full+movie+free+watchPDF 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_off0000d779.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD779 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF8B 17172 bytes
SHA-256: 2c19459fdd1f81e0f36696bf54a04c38ec7a13a524a36ff4a60815ce13282217
font_02_sfnt_off00011c62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C62 11020 bytes
SHA-256: 2dece6da803990e53ce3c60f508ef90b651969e7b9310a675594c1d7a7197611