Malicious PDF — malware analysis report

Static analysis result for SHA-256 81acd6f9f83944f5…

MALICIOUS

PDF

73.4 KB Created: 2021-09-30 22:38:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 63704cbdbb840cc2afd442f5964031aa SHA-1: 9ea93d8315cc4f2d970d9255e4173b8f7b2a58cf SHA-256: 81acd6f9f83944f5f5e4a407cc562226ed9ec658ecb1dda09fdb7098218d1f2c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://oniceh.ru/uplcv?utm_term=configurar+audifonos+iphone+en+android PDF link annotation
    • http://amongelite.com/ci/userfiles/files/rinid.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/60257415692.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/5bd3cb73eab32269aa2c48be4b1b06ad/sepabevuzadezorulut.pdfIn PDF document text
    • https://kuwaitpolyurethane.com/ckfinder/userfiles/files/mewedexapes.pdfIn PDF document text
    • http://cualuoiskydoor.com/webroot/img/files/65787404630.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/93058560888.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/gobojotunilenub.pdfIn PDF document text
    • http://decaiyun.com/upload/file/210902134249016932gvf04n6ya1o1.pdfIn PDF document text
    • http://stluciachamber.org/uploadedImages/contentImg/file/46637518727.pdfIn PDF document text
    • http://woodlander.sk/grafika/file/dakuwe.pdfIn PDF document text
    • https://gilboamedia.com/userfiles/file/71165531138.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/485741d84e003fc3ef674a4541414569/getaxoxinefi.pdfIn PDF document text
    • https://electrodomesticaruano.com/images/ckfinder/files/50997208319.pdfIn PDF document text
    • http://dydlhx.com/upfiles/file///nazaveporisasefogakisexu.pdfIn PDF document text
    • http://talk200.com/admin/admin/uploadfiles/file/73545833640.pdfIn PDF document text
    • http://postelezmasivu-brno.com/ckfinder/userfiles/files/66493353463.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/54040673409.pdfIn PDF document text
    • https://mashura.co/userfiles/files/xeseni.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149d097be563---funibi.pdfIn PDF document text
    • http://hvezda-pardubice.cz/files/file/8634170215.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/33197179058.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/jupk7kmdao133v7222kn0oa006/40874283994.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/nipowinisadetizami.pdfIn 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://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_off0000b968.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB968 10764 bytes
SHA-256: f06bdda5ebddc6989b7e8f480daf7d5bd192e78aa064ac92b341d13e57fff165
font_01_sfnt_off0000d1ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1EA 17744 bytes
SHA-256: c6e4ff8c70f77086f2dea3c5f2e6f81135aa0dc1d3ed0cf438ec2c589370b2bd
font_02_sfnt_off00010008.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10008 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1