Malicious PDF — malware analysis report

Static analysis result for SHA-256 af8b0651f4a7f964…

MALICIOUS

PDF

93.4 KB Created: 2021-09-17 21:48:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 704d1084e5c7eaccb5ff07ee56a2679d SHA-1: b225984923a5927410ffae27181ccdd960b6e742 SHA-256: af8b0651f4a7f9643847b4f1097cec0f0e7600ef1d871b24f9d41e5dc513dd93
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to websites hosted on compromised CMS platforms or disposable hosting, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is unreadable, but the heuristic firings clearly indicate the malicious nature of the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://www.azurwelcomeservices.com/userfiles/file/nuvapi.pdf In PDF document text
    • http://archi-m.ru/userfiles/file/25221047886.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161368910bc9e4---fufar.pdfIn PDF document text
    • http://greece-ex.com/images/blog/file/99974528020.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/532690ecd68d2f2a66cb35b0f09e44a4/92012596364.pdfIn PDF document text
    • http://pegasomeeting.medcoast.net/ckfinder/userfiles/files/4108306413.pdfIn PDF document text
    • http://kyanite.tv/userfiles/file/42594264097.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/xusaw.pdfIn PDF document text
    • https://fetogram.com/images/upload/files/8319582863.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161330bfe4057c---maninirivapobutazapaj.pdfIn PDF document text
    • http://madinagirls.com/easydo%20v2.00/files/uploads/sibanuraves.pdfIn PDF document text
    • http://paletydozahrady.cz/ckfinder/userfiles/files/bolumaramezixulegeb.pdfIn PDF document text
    • https://ofly.om-digitalsolutions.cn/upload/files/najalulapi.pdfIn PDF document text
    • https://escaletravel.com/userfiles/files/98107564609.pdfIn PDF document text
    • http://paroissedementon.fr/upload/files/25967256097.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/97885752158.pdfIn PDF document text
    • http://basaritarim.net/admin/editor_resim/file/dimuxujuneforemasupese.pdfIn PDF document text
    • http://sport-zavora.cz/data/file/jafitadetitame.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614389d0dbae9---mewuteve.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/sepos.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf89846946---37624106980.pdfIn PDF document text
    • http://hcstonetw.com/uploads/files/202109131904095167.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=amor+y+responsabilidad+karol+wojtyla+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_off000102ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011ac4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AC4 11200 bytes
SHA-256: feee006685b0344e00c8607e65b637334ed802e2a6f9b54dfd6fa7e8f9a42c9f
font_02_sfnt_off000134c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134C9 19800 bytes
SHA-256: d29b378a5da917bc96925afac677a2bf3e9685be26ef30063c96a808f0537eb5