Malicious PDF — malware analysis report

Static analysis result for SHA-256 57c73e5a1567b393…

MALICIOUS

PDF

87.4 KB Created: 2021-09-23 00:45:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0923f9dec24ee7c3e2d10de317f44f63 SHA-1: 3243caac74b463bed955356a92bb413e11f3509c SHA-256: 57c73e5a1567b3938df2122707e7820c124b06a6114c3da8ce3fa2a30b1109ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to obscure malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://ewt.cz/res/file/31089108273.pdf In PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/161392b5c38a69---sogozefel.pdfIn PDF document text
    • https://onderdurdu.com/upload/ckfinder/files/64689129796.pdfIn PDF document text
    • https://anandalaya.in/resources/file/levexibukutamol.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/161460f0291934---suzev.pdfIn PDF document text
    • http://iberia-ex.com/images/blog/file/namumofenukasibaborikusud.pdfIn PDF document text
    • http://erodiertechnik-wenzel.de/userfiles/file/wiraselabunijebukepu.pdfIn PDF document text
    • http://pharmorgsyn.com/upload/files/52724208085.pdfIn PDF document text
    • https://narellesastro.com/userfiles/files/39509968118.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/dubulabezepimawope.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/fc98e658129beda41b3089e0d0605d39/1490201136.pdfIn PDF document text
    • http://www.andreapondika.cz/file/safulet.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/2820851194.pdfIn PDF document text
    • http://maradonasalud.com.ar/ckeditor/ckfinder/userfiles/files/kijuviduwiw.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/votodozumefopanoret.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/1757138862.pdfIn PDF document text
    • http://azinsaghf.com/cache/fck_files/file/jemovewerorutamuwanuzeni.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/34263869016.pdfIn PDF document text
    • https://tumujerrusa.com/userfiles/38031214833.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134be7c30987---54273399059.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/46509503445.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/11035882831.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/47685520036.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/94534244103.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=how+to+get+free+robux+easy+2021PDF 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_off0000ede2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE2 18776 bytes
SHA-256: f73d5173157fa5f1e903a28ff057598177ea8103762e1a5b5a095c8fa033825c
font_01_sfnt_off00011e7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E7F 10972 bytes
SHA-256: 3b4c768aef680c198a200bcc7dda16debcb70d9ebd7f3c52280e303f89d0d077
font_02_sfnt_off00013854.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13854 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1