Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e79a4797fedde1b…

MALICIOUS

PDF

95.7 KB Created: 2021-09-24 08:10:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 5891bfa935a520efb1120970e93d28c5 SHA-1: a87277a82eb35fa261d8dbd23976df486eba1722 SHA-256: 9e79a4797fedde1bf4b96903aea8b97abdee4dfb85eb0d9d66f9638bc2ad44b6
156 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 links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and the nature of the heuristics indicate the file's primary purpose is to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://anhhuynoithat.com/asset/files/jufolutisaxuvovomam.pdf In PDF document text
    • http://rnralpha.cz/res/file/digaseperenunuzolaxovoful.pdfIn PDF document text
    • https://bdlvn.com/steel/upload/files/46397201811.pdfIn PDF document text
    • http://etkenkalip.com/files/silosorotirasuwomi.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/802cc0584f0654123ab3db8c5a1502a7/nevewusafa.pdfIn PDF document text
    • https://e-ceramika.pl/userfiles/file/52985612710.pdfIn PDF document text
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/niwedivugavimilopudu.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/61201374848.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/18486950978.pdfIn PDF document text
    • https://stephankeppel.com/userfiles/file/76896715644.pdfIn PDF document text
    • https://euroialinsol.ro/userfiles/file/pexotoxoragaxubamipiwo.pdfIn PDF document text
    • http://shipsupply.ru/userfiles/files/niwowebegez.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16134fd588b752---68499299005.pdfIn PDF document text
    • http://elsped.hu/files/file/88263263374.pdfIn PDF document text
    • http://a-b-i-s.net/layout/bilder/file/fitigezogezavajepuxu.pdfIn PDF document text
    • http://panda-es.tokyo/yamituki-n/uploads/files/15239443607.pdfIn PDF document text
    • http://juncheng.tw/upload/files/dosadixukobezoniriwifigi.pdfIn PDF document text
    • https://norservis.cz/files/files/57717371117.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141560014f54---77793557822.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/de3e5054cb580fb39e1ca547eefd101d/7153820269.pdfIn PDF document text
    • http://studiochiodo.eu/userfiles/files/jugabeso.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/jejubofusedaxup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+app+to+sd+cardPDF 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_off00011320.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11320 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012b37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B37 10212 bytes
SHA-256: 213fd9a666fcbdf27b89272fc1bd8829bd4b2d6ae35c0cc1bd756e6dbe80feb8
font_02_sfnt_off00014247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14247 18308 bytes
SHA-256: 528c51c8aaf38e5812016c30d57495e83fd303539a2ea28a4a1b728bd923c48e