Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d87faa11baf8f2…

MALICIOUS

PDF

72.7 KB Created: 2021-09-10 07:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e206e479e0fb667a8c11e2cae89678b8 SHA-1: 83f2c1100ef6ba2ae63c61383239e68cf1d5f80f SHA-256: 91d87faa11baf8f22d7a062a639aa6912590691971266cff5466a73a1b0cfa44
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. The document contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious content or phish for information. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicate a strong focus on directing users to external, potentially harmful, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://wastran.ru/uplcv?utm_term=samsung+galaxy+apk+apps PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613965400f24c---12703073561.pdfIn PDF document text
    • https://zoldlaptop.hu/ckfinder/userfiles/files/39466751945.pdfIn PDF document text
    • https://valeaflorilor.ro/img/uploads/file/nekuxanipipisubazu.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/93622901200.pdfIn PDF document text
    • http://daugiavanthienphuoc.com/media/ftp/file/letelugozo.pdfIn PDF document text
    • http://congluc.com/upload/files/36434351772.pdfIn PDF document text
    • http://daejonggyoyc.com/userfiles/file/20210902151908.pdfIn PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/bofetof.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/161318c7c7e196---kesuvobawigobudibow.pdfIn PDF document text
    • https://krzczonowice.pl/gfx/file/webebatux.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/161316b9c1de54---75169263395.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138db6907158---lorudekagopaboxuradi.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/79322937152.pdfIn PDF document text
    • https://himalayanwanderer.com/himalayan/userfiles/files/28856649269.pdfIn PDF document text
    • http://intproplaw.com/admin/uploads/file/65541406632.pdfIn PDF document text
    • http://madinaboys.com/easydo%20v2.00/files/uploads/23283236257.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/67284316211.pdfIn PDF document text
    • http://peaceinsrilanka.lk/ckfinder/userfiles/files/dowaziwuxiwif.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210907_180137.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/46151327063.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/491f09264e9143a3d2bb7ccfc720e428/gevikufexopod.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/ag2et7fqjnulnpk9lt9gdugjpe/tojotasinolutu.pdfIn PDF document text
    • http://stilna-ya.com/_userfiles/file/xobiboja.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_off0000bb93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB93 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3AA 10536 bytes
SHA-256: da3738a2dd71e1fee97e56122b051781340f56359e67086cc4074ef46eea4b48
font_02_sfnt_off0000eba4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA4 16228 bytes
SHA-256: 514808065ae366af020216d0334f4685427c718c94b46db50cd27884366b46bb