Malicious PDF — malware analysis report

Static analysis result for SHA-256 5916d840d55b108b…

MALICIOUS

PDF

79.7 KB Created: 2021-06-19 23:36:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: cf4b811c46b7b32560768ba94bffb1cc SHA-1: 9b77653b5df865fcaf7ade0745cda10704f2f3c4 SHA-256: 5916d840d55b108b9ef784fcf266d89e49243794bea76f482571a1e49842ffea
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous external URIs and link farms pointing to compromised WordPress upload storage and disposable hosting, suggesting an attempt to redirect users to malicious sites. The embedded content, though heavily obfuscated, likely serves as a lure for these redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://chcial.ru/uplcv?utm_term=havana+on+piano+easy PDF link annotation
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/06bc3869568180abe87a749508b4c7a6/2779423773.pdfIn PDF document text
    • http://email-database.info/userfiles/file/34899202602.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/ht7k14noq651pt64m6oaha7hlr/zekebunalab.pdfIn PDF document text
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/f8c172b88319082f5bcd98d0830790b5/90589376633.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/8eb3448d0c20bf78bc1a709191b05b28/71522143038.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5a9bc4d1d---66296514380.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd4c77cf93---81082179921.pdfIn PDF document text
    • http://abnicum.com/files/file/64920388118.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5a78592e4---fitab.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6f491f022---wajifefijopunilatixixore.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/vopop1cgvu2voof31m7l3eroi4/74458046817.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/be156d70744e967d2af847f390b90c79/juvalilevurixepusasuk.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/cpc47po8beqc1klb0jj2b3foro/gavijag.pdfIn PDF document text
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/97a96e4967ca1db6c02b9a42d61afab9/86531801932.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/160bf8ccf9a94f---56106461329.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608f03440889d---topezobuwubasa.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/o8r8cp2o2m0er0uhbamn3ge6at/44087620730.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB46 4808 bytes
SHA-256: 8d6590bb375e223f9ac44229205bf685e091fdd22d403eb8b17fceb9f0c31be6
font_01_sfnt_off00010bc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC1 11324 bytes
SHA-256: db608576507147425a132105e99112b01c2546698b7420efc5b85ef48334de1c