Malicious PDF — malware analysis report

Static analysis result for SHA-256 d17c040bb9e32f46…

MALICIOUS

PDF

70.0 KB Created: 2021-10-01 13:55:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: ee55bcba1e32162a6093bd10ed149f2f SHA-1: 8496cb3b29f52371dde449e16f6d6ee271bb6fa1 SHA-256: d17c040bb9e32f46f7ddbe2b81b112a776d534f2be5c2d3a2db17a20d8f314e6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, and contains numerous embedded URLs. Several heuristics indicate that these URLs point to compromised CMS uploads or are part of a link farm hosted on disposable domains, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious intent, likely to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://coretry.ru/uplcv?utm_term=k+means+clustering+theory PDF link annotation
    • http://pospatrans.cz/UserFiles/File/60240804768.pdfIn PDF document text
    • http://baodieptailor.com/uploads/2021-09-02/images/files/94090760987.pdfIn PDF document text
    • http://sarica.com.tr/ckfinder/userfiles/files/85022205100.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/virunapilelokedokiz.pdfIn PDF document text
    • https://gianlucabruno.it/dati/upload/file/97714075435.pdfIn PDF document text
    • http://asesorgubernamental.com/images/file/19918999727.pdfIn PDF document text
    • https://ubk-sad.de/azubi/userfiles/files/zejimot.pdfIn PDF document text
    • https://cargotavio.ru/files/file/99382472567.pdfIn PDF document text
    • http://everestlodgelukla.com/userfiles/file/38895009614.pdfIn PDF document text
    • http://z-him.ru/userfiles/file/dorejizuwel.pdfIn PDF document text
    • http://drcleancenter.com/uploads/files/202109200214373555.pdfIn PDF document text
    • http://huiking.cn/uploads/file/040829221322.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16153bcde24d26---vuwufamirib.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/aaf154aad11b1f21646979868f16f02a/61330028157.pdfIn PDF document text
    • https://chetanaus.org/bheru/uploadfiles/file/87126525615.pdfIn PDF document text
    • https://alistairmills.com/ckfinder/userfiles/files/51338453823.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/folerunajajamuvaxefovo.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/up6fok1efl4ninf7e0js5g6mi4/fusiwinokufinikoj.pdfIn PDF document text
    • http://volkshilfe-ktn.at/images/content/files/mozusowenegifo.pdfIn PDF document text
    • https://aynispirit.nl/userfiles/file/53421629086.pdfIn PDF document text
    • https://implantologie-deva.ro/app/webroot/files/userfiles/files/20490434097.pdfIn PDF document text
    • http://curvesncontours.com/userfiles/file/18981185374.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210905_7D8523DEC1E1F7BE.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_off0000b10d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB10D 10884 bytes
SHA-256: 8c348046558371a7101ac5661561886fbf8394f38597d20392c8fce9a0ef5979
font_01_sfnt_off0000ca04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA04 15768 bytes
SHA-256: be41febe8ce2505d216a8703ccedafac45a6b1910dedbfc18cc102f1053c30d5
font_02_sfnt_off0000f248.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF248 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1