Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac9433cd103d9372…

MALICIOUS

PDF

78.4 KB Created: 2021-09-09 01:15:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: bbe3e79efd83ed436d0d03e193c67f4d SHA-1: 379c08e6a4e152c183ccca42a9533679726f0700 SHA-256: ac9433cd103d9372327edbee98071835dc69eafcb8c99dd43ab8af248eb19f42
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, likely intended to trick users into downloading further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent. No scripts were extracted, but the presence of numerous external links and the nature of the heuristic firings suggest a phishing or downloader attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613383e3f3b26---mukabaxovejizobolutef.pdf In PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/ridarug.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/vejidix.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/74512989487.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/96894711249.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/64191811895.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/pajoz.pdfIn PDF document text
    • https://miguktour.com/FileData/ckfinder/files/20210902_6BA912C844286145.pdfIn PDF document text
    • http://skene.es/userfiles/file/vepiximixafejawivejal.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161316071c072d---pikiwu.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613510e7bcb03---40157711411.pdfIn PDF document text
    • https://vanvoorst.info/uploaded/file/tarifutenadapokekobipiz.pdfIn PDF document text
    • http://webcertain.ca/contentupload/fckeditorUploads/organization_/file/84870020821.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/37178187196.pdfIn PDF document text
    • http://aktifimmo.lu/userfiles/files/34084195575.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1613185f0c57fe---79483677986.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f76fb80ad6---daxizosiw.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/21b1287a1a684fa1490d50577b9e1eef/15528251013.pdfIn PDF document text
    • https://kingcarmotorista.net/uploads/files/42347069249.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210905014338.pdfIn PDF document text
    • http://perfectprojects.ro/userfiles/file/jibedididizufarafunigef.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/92516298427.pdfIn PDF document text
    • http://decorstore.eu/upload/file/53418821480.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/jifezafokot.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/64397374742.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/88132519671.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=carrom+pool+new+version+apk+downloadPDF 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://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_off0000cb03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE31A 10728 bytes
SHA-256: cdb0c2c87b91d722c444ba14b6c1285587eaadf0a5e79e77b621b7503c9ad09e
font_02_sfnt_off0000fbbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBBD 18352 bytes
SHA-256: d3fd7a7903ac16628215202432acbf8660ec8756941b8d9be261ecdcf31ea14e