Malicious PDF — malware analysis report

Static analysis result for SHA-256 13553d3934364599…

MALICIOUS

PDF

73.8 KB Created: 2021-09-07 15:35:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 3ab296d3255f772700f9d3271704fbdd SHA-1: 4d30c0890afe115b38f79dc7387913ea351c771e SHA-256: 13553d3934364599afe0380e770241ef02a8ec279bdd057caf4d3576d939c00e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also contains numerous links to external websites, many of which are hosted on disposable domains or compromised WordPress installations, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chokmanee.com/userfiles/file/vupakeves.pdf In PDF document text
    • http://giayviettri.com/img-ftec/files/bevilikukejogoxulugog.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/udvqnjcdhr8f5jrmkjhd13opcg/49120330068.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/b8h18ecmm2hifc0u5klpkjss5a/neses.pdfIn PDF document text
    • http://plusk-car.com/js/upload/files/seteku.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d9d5215407---88511548311.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fed36ed0aab---pisuradutepewigazivuka.pdfIn PDF document text
    • http://airelimpio.mx/img/editor/file/44913834956.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/bb2ab14a2aa8717945fec1d853f12dd9/tezekelodojagesikizibex.pdfIn PDF document text
    • http://wxdyzs.com/userfiles/files/wuguduselefa.pdfIn PDF document text
    • http://aotwresort.net/ckfinder/userfiles/files/jigagufupubofozilil.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/302cbc4a2403e1a0dd4bc81275eaa9a7/dexekaf.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/6453cb8790258f6ef2c2b5d8c6ac712f/8829953318.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd4bb0c4f04---nuxiso.pdfIn PDF document text
    • http://vladekoservis.ru/files/83442949316.pdfIn PDF document text
    • http://mopi.eu/ckfinder/userfiles/files/xoretemawufetazoba.pdfIn PDF document text
    • http://antwerp-reefer-tournament.be/argt/files/jigoxogilatabesuzadud.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c50291db9c---zegozalataza.pdfIn PDF document text
    • http://primethailand.com/ckfinder/userfiles/files/xabepebewis.pdfIn PDF document text
    • http://jinsonmetal.com/Upload/file/21805940491.pdfIn PDF document text
    • http://christopherdallo.com/file/kogevutepaxasefatod.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9902a632c4---2917476579.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/502a36fbca3ffea5f3cff6f502bcf880/33725915448.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=geriatric+nursing+review+syllabus+pdfPDF 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_off0000bbee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD405 11220 bytes
SHA-256: 555a045e3652891d45e2c4fe790ad52aca91553eb2abb6bb0cb17b7c7c6b0afe
font_02_sfnt_off0000ee18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE18 16968 bytes
SHA-256: 08ff6cf5688ff3df0469c7fc3fcdc9cfd835df829ce27a97d36ff8007e7e014e