Malicious PDF — malware analysis report

Static analysis result for SHA-256 50c57cbd0300d30a…

MALICIOUS

PDF

84.4 KB Created: 2021-07-02 00:30:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bc52e63d98e339a440f72fb1be5e423c SHA-1: 6872d113ea252201279fde128cd5fb41335df09c SHA-256: 50c57cbd0300d30a4741bf42ad95e7d4e8e419b416d5949dd8f536486004bf33
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 external sites, including those hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://espacioschillout.es/images/admin/file/gisisosuwan.pdf In PDF document text
    • http://www.firengo.com/userfiles/files/liredajevogamebif.pdfIn PDF document text
    • http://ratchadatitan.com/UserFiles/File/xaguxizujobifavufemijopij.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/0b77382c570ec7002b0c2a37a18df095/jelowuxamovoteke.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/18674070259.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/dau9g5st5g05d6b61qet78g354/tudelenumetasamabipuja.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/1b0466e6610dd1d863149627de06e80f/23765449089.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/935f9b11cf613677891037f91aa36849/84540099618.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/ll4sesva3ojqd643ilh3ktsunl/belotorulejajenodibo.pdfIn PDF document text
    • https://rintrans.com/files/79103093136.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf10306365---zazodedisodef.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca1a4abaaa---soboxabutimoxa.pdfIn PDF document text
    • http://trhs64.com/clients/c/cf/cfad56e582d93fa9eda51f2516e23bdb/File/tozikumazufuj.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/612046c37e0bfd0aafc8352e5bbe38b7/lizuzunebig.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f63694baf6---12667755583.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/75031757166.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/a4a2e5f7b71814605b36f32daca9a9f8/62500746212.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/b720d6f4bf6608239cd28a7db2d88fc4/19831515944.pdfIn PDF document text
    • https://tungafilm.com/dorceiys/ckfinder/userfiles/files/36772931707.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/83571540944.pdfIn PDF document text
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/460a7d89cd812a2a291214cc8419458b/17088311239.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/4770d456b7ce8aabad46756199509399/dideviburised.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/10661072263.pdfIn PDF document text
    • http://climtech.com/files/files/72594164787.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609aed8a5a891---pixejusir.pdfIn PDF document text
    • https://argumentua.com/i/file/42609275715.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/xipodi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=mark+message+as+unread+iphonePDF 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_off0000e65b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE6D 17240 bytes
SHA-256: 6126e613555d4ce5403f8cf33032ff27c4f929f2551468aef672fa485b205a84
font_02_sfnt_off00012b77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B77 10880 bytes
SHA-256: a4f7b0b3d0dc42c6aeecf1429a4b4353b14226aa06155b5c7bdf901f4d3633d3