Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c99b5d7341ce301…

MALICIOUS

PDF

74.8 KB Created: 2021-06-23 09:02:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: ecd97111ba17cf2c6fef4dcf3760e307 SHA-1: c35cb059d569340c1de8344ef077925e62b059b1 SHA-256: 6c99b5d7341ce30169b30c325fa52f0a3c8f97c26253f77bd7bc7aeb758aef40
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to deliver second-stage payloads or redirect users to malicious 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://longhoang.vn/upload/files/pavibejegapamiki.pdf In PDF document text
    • https://implant-drill.com/userfiles/file/94852750883.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160879b5d1bf42---tuzevinemogu.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/924b130443803c25471d0543797dd43e/jibatokuvavivikurudavexu.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/59926154032.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/59949804747.pdfIn PDF document text
    • http://advicetao.eu/pictures/file/bokudirajike.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/25268624755.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/1fddb66e8076b1b8b12cba0f11ef34f5/57016463953.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/16090e6e27863e---95778304881.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1fbdec709f---66296993092.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/kl4s3f3uusa574l46nblmd28j8/fupagefuxujogipukage.pdfIn PDF document text
    • http://sola-brothers.com/userfiles/file/70292788047.pdfIn PDF document text
    • http://trendymamy.pl/userfiles/file/midasededataregiwavabof.pdfIn PDF document text
    • http://dh-life.com/ckfinder/userfiles/files/17178509510.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=orbit+57900+owners+manualPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD637 2112 bytes
SHA-256: 6b35e0528f8bc9e0369c78a462037e87f8896ab7eaf6fa4a004341948c7662df
font_01_sfnt_off0000dfd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD2 5592 bytes
SHA-256: a10e54292d929c4c15bbe4200c79e402a674fc3ff61bbd2873eff39640af9253
font_02_sfnt_off0000f2d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D8 13476 bytes
SHA-256: b04da2c03e8661c04dd71b7a0c35aebd73847fed1b5eb14fc3b9fb933e6f0de8