Malicious PDF — malware analysis report

Static analysis result for SHA-256 b85abcd58ca9d1f6…

MALICIOUS

PDF

128.7 KB Created: 2021-07-14 07:31:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fa05c53e74a77b9e7f46767b5fa1578c SHA-1: be736aed490c878c48320342b0ee91cea627c584 SHA-256: b85abcd58ca9d1f6415edfddb8aa0a5233b8bbfadaf0671f049daa66860694f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, so the primary attack vector appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://synerhu.ru/uplcv?utm_term=when+is+prom+in+high+school
    • http://fvv-hohenfelde.de/sites/default/files/files/mizuloxugegewasapedidu.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093351a6ddca---10862087012.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8d90cfe24---gijobelizetevo.pdf
    • http://laclonghotel.vn/upload/files/jofijejono.pdf
    • http://svatba-emi.com/uploads/pages/files/fabukiwizedigutadixoniga.pdf
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/99d45301b8ea26b779447a43fea51087/menikenimenami.pdf
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/sj1po16svqs5l741upl80tbqce/foxifujasesakarixuvatiwev.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16092e4e976e2a---tolala.pdf
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2d04fee2b6---42552589895.pdf
    • http://alpha-th.com/userfiles/file/xozavupazirisuvep.pdf
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/ec6f2064f12f98798534b24eecd4be32/14696747713.pdf
    • https://linhngapt.vn/upload/files/ximofavepijasotalagafuwok.pdf
    • http://xn--12cmi2byac9cdhd0hra6d7bxkwbgj1gch.com/user_img/files/linutabakemu.pdf
    • https://www.llgnjinc.com/wp-content/plugins/super-forms/uploads/php/files/da1f1f95df9dea2dcc7ec3093fc868b1/13575801661.pdf
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/80f445f74b7c03020f34997e0f0a423d/dajugilijomu.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160e02e3b7bae3---15820684823.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16070723b687fd---fonababedufo.pdf
    • https://advantagelic.com/singhania/downloads/file/24159283779.pdf
    • https://stopserv.ru/files/file/82346387526.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00018c38.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18C38 16792 bytes
font_01_sfnt_off0001a44f.bin
d238068ce0844280d3fdbc636e7cca5b5962c164e266f9da37dbe385f19e380a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1A44F 10552 bytes
font_02_sfnt_off0001bc1d.bin
e4ccc5a52c9a4c4b78343044d339ee576e042ae01acce06d339a4f6299b8a555
pdf-font-stream PDF embedded font (sfnt) at offset 0x1BC1D 24380 bytes