Malicious PDF — malware analysis report

Static analysis result for SHA-256 23a73d6afcbafee6…

MALICIOUS

PDF

126.1 KB Created: 2021-06-11 08:30:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 5b7f3f24add18c6615018fac9385c8c8 SHA-1: adbcbd23c6e4703d0ab0ff826b87e6c746449568 SHA-256: 23a73d6afcbafee65aa8dc16f2790cfd77df61b4a9b09c579ba9c7372c8b3998
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link T1059.007 JavaScript T1553.005 Security Software Installation

The PDF contains numerous links to external websites, many of which appear to be compromised or disposable hosting, suggesting a link farm for phishing or malware distribution. The heuristic 'SE_SECURITY_BYPASS' indicates the document may instruct users to disable security software, a common tactic in malicious documents. ClamAV detection as 'Pdf.Phishing.Trojan' further supports the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://medvor.ru/uplcv?utm_term=form+1040+schedule+c+business+codes PDF link annotation
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608848401199d---dirifiguvogopokifo.pdfIn PDF document text
    • https://pioneerlift.com/upfiles/editor/files/12114116156.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c06707f2aaf---48348195004.pdfIn PDF document text
    • https://capitaleny.com/wp-content/plugins/super-forms/uploads/php/files/22cb04b30602b15bbf42e6adfada0f64/12091691045.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/f3r3d9t2o8b1ktp1i0r9utaitb/tilafobazavelixuruvupaz.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099d3425f8a9---tuzufodazuvo.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/1nbsb4rt3krauld33jaqa9cbc1/sigejotad.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a68df92e38---21329277235.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa82aedc82---71082577214.pdfIn PDF document text
    • http://vinmexindia.com/uploads/keniridusi.pdfIn PDF document text
    • https://frontlinetherapist.com/wp-content/plugins/super-forms/uploads/php/files/7f0b7b4b92af12bca8f7ada22eb677ee/19364818965.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/6acb7dd6b1434857b28638d7f958ea6e/98147408477.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/799b59f315e83eb7f0290eca05e47df8/kopukine.pdfIn PDF document text
    • http://yossy.biz/userfiles/file/kukuvonajinipepijavav.pdfIn PDF document text
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/3be71acd5a0505c30c67856bcb654917/54417421576.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_off0001b380.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B380 5344 bytes
SHA-256: e96e2dbeb955f80f8b84c95b8c9c5efcba92b02b73cd32f47fc63658ea74bfc5
font_01_sfnt_off0001c589.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C589 10952 bytes
SHA-256: 867769ac75a53828a8b05238f79dcbb8ffd28d8d96b49bf12a544d42d62257b7