Malicious PDF — malware analysis report

Static analysis result for SHA-256 08f28153ac406326…

MALICIOUS

PDF

81.6 KB Created: 2021-09-20 04:59:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e376cbe2e361c3d4c14be8540a95bb1c SHA-1: ce1217556b966b00238a4a4574fc3e3d1c05edd8 SHA-256: 08f28153ac406326809792a71d8d5d0ea247e0250fba6678db63a59547b3ff69
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://nomylo.ru/uplcv?utm_term=how+to+hide+previously+installed+apps+from+play+store PDF link annotation
    • http://dabaizhongxue.com/upload_fck/file/2021-9-4/20210904183435734564.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/fapavulususik.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/kuzokizem.pdfIn PDF document text
    • http://abwrva.com/uploads/files/98017747436.pdfIn PDF document text
    • http://santeh.md/img/files/musefuzagamate.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/24877919162.pdfIn PDF document text
    • https://holyfamilyhospitals.com/ckfinder/userfiles/files/votakuzoz.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/247973017.pdfIn PDF document text
    • http://goang-hann.com/uploads/files/202109111338232295.pdfIn PDF document text
    • https://www.smartfutureexpo.com/ckfinder/userfiles/files/36584126845.pdfIn PDF document text
    • http://vcelari.naceradec.cz/includes/ckfinder/userfiles/files/farijirig.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/58639916000.pdfIn PDF document text
    • http://tuderprogettazione.it/userfiles/files/rejut.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/39726267471.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e37d73a82---sutopugudotukurijidiw.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed1c39ba17---demaxadejofuzox.pdfIn PDF document text
    • http://szigmetal.hu/editor_up/gonezepogazul.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/f9dd9a27fb274d1beda591230859b64a/mumukogul.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/496614deeeba5739c5e1bad377e69285/keduti.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///16623731671.pdfIn PDF document text
    • http://xn--j1aai7d.xn--p1ai/userfiles/file/gizivaginoxib.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0f9dd26f5---rewedexoremosok.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_off0000d971.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD971 17352 bytes
SHA-256: 6b591de7b7231b9df241eae4b4122653be32c294679ee6b1132d564458cbfc3e
font_01_sfnt_off00010648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10648 11120 bytes
SHA-256: 6881c88aafc87cdadb3f7b99d4329b2167cb4e390699ca04dfefe08f626099ea
font_02_sfnt_off00012015.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12015 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1