Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f38bdcc7bb129f8…

MALICIOUS

PDF

91.7 KB Created: 2021-09-15 10:07:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8548af9ce0a9028d87d492784f1f94e2 SHA-1: 0f5c5e5652d8fae259c0415974a23444bff2e1cc SHA-256: 4f38bdcc7bb129f8802e106257e756219f66e8e0b1b74e32bc2150c5ba31f3ca
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to external domains, many of which are structured as link farms or disposable hosting, indicating a phishing or malware distribution attempt. The `wkhtmltopdf` authoring application suggests it may have been generated programmatically for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=pes+2018+ppsspp+file+download PDF link annotation
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/wisupemeganutawozerexam.pdfIn PDF document text
    • http://svb-volleyball.de/userfiles/file/wonodurivifolotisaze.pdfIn PDF document text
    • http://globalsocialwlefaresummit.com/app/webroot/uploads/ckuploads/files/varanodawow.pdfIn PDF document text
    • http://mastervgtour.by/var/upload/file/17970360061.pdfIn PDF document text
    • http://nscenter.cn/upload/files/73816686265.pdfIn PDF document text
    • http://pokwuttibut.com/file_media/file_image/file/64931849434.pdfIn PDF document text
    • http://zamgph.com/FCKeditor/editor/filemanager/connectors/php/uploads/file/042101548581.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/161362fbbe0626---37370442999.pdfIn PDF document text
    • https://winstar-tools.com/UserFiles/editor/file/28796727482.pdfIn PDF document text
    • http://zimmerei-possert.at/91423271620.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/3913974024.pdfIn PDF document text
    • http://fthyhs.com/resource/docContentImg/file/2021-09-03/51b884b8a1a6cdbe24eb8f4302e2f12a.pdfIn PDF document text
    • https://wanna-drive.nl/files/File/70725965984.pdfIn PDF document text
    • https://gkia.org/kingkong/userfiles/files/xadizutasukokibofepoduxo.pdfIn PDF document text
    • http://bangladeshceramicsociety.com/uploads/editor/files/9714558868.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/bovosabojepajukuxokujub.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/27904545721.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109130500078007.pdfIn PDF document text
    • https://zzwgjx.com/d/files/92976117069.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/tivitedu.pdfIn PDF document text
    • http://worshipedia.net/sites/default/files/file/61371449681.pdfIn PDF document text
    • http://hrudolf.com/userfiles/gudiloropa.pdfIn PDF document text
    • http://budka39.ru/files/32314168774.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_off0000ff7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011792.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11792 10884 bytes
SHA-256: b53f9c39132898e76ba382149e20e316edf9de0717dc31bf22f26c9d773d01a0
font_02_sfnt_off000130fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130FB 18616 bytes
SHA-256: 56315c99c38cdc60ab2364946de8b85684e864d5b89422309087def29c90c0ef

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