Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b0aa138dc80eba4…

MALICIOUS

PDF

79.0 KB Created: 2021-06-18 13:44:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 7d22fc2090e54a411b4dffb46c84c5ec SHA-1: ba4b59e3e79e36fcb26fe2d0411d2b4c6157fb92 SHA-256: 5b0aa138dc80eba406cb2002546a2293a61d0132a0e8aeea987f91c6d505633e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded URLs pointing to compromised WordPress sites, indicating it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this is a phishing or malware distribution lure. The ML classifier and ClamAV detection further confirm its malicious nature, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. No scripts were extracted, but the primary attack pattern involves redirecting users through a network of compromised sites.

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://huntic.ru/uplcv?utm_term=character+traits+list+pdf PDF link annotation
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16073e833cf7f5---xifuwixuzu.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/4247f9564259dfa8246bbca2f3a7e28d/rarepopenanenolefam.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/o5r0heah6kpe3obu9f6tnithfn/bezudigofu.pdfIn PDF document text
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/a54d6e68caa73e705d5d91be93c91162/85216341533.pdfIn PDF document text
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/f271e9991854a841459866251e465d47/benibaviliforitowolipef.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160703fd42ba38---61741424884.pdfIn PDF document text
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/kajetike.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b08b2800be9---zipomolumu.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/vuk23bppo96kro2ln5309iphh1/ziwulekaxudow.pdfIn PDF document text
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/gawowuwov.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1608fc6a5b2704---rumapexowelerixufegogerag.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/sazogujimobozaze.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160941d096fb85---nojemurinez.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
    • 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_off0000e4e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4E9 5148 bytes
SHA-256: 9b05dfbea2618557c33c12a04452518e29b38c46c7086ffa102c5b4351142bf3
font_01_sfnt_off0000f65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65E 10668 bytes
SHA-256: 96ff4c6d2762e3b61233db643c437cd11fd84eba42693c760e605e7368fcb058
font_02_sfnt_off00011a71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A71 16060 bytes
SHA-256: 18c238ad931013c02f8b9edf520ceec5ec83417eda11db08e4be278b2e55a3cf