Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a8b7a8c7acebad…

MALICIOUS

PDF

69.4 KB Created: 2021-05-06 20:19:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: a74eb60c32585e5b7d6deb8ab6aacde0 SHA-1: 45b3e6362daef381f91a75ea660183793044d662 SHA-256: 31a8b7a8c7acebaddc13dbd9a421673ccda4fd1f0fddde64e37e0fad61d23b63
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute further malicious content. The presence of PDF link farm heuristics and embedded URLs supports this attack pattern.

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 http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160724f23716ab---72159814371.pdf In PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/85c91e6b5c8b34333e7fc26f2722968e/25445543493.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/96be8b0e394945f04cf082f539096b2d/lewiduxasunudowos.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/a1d0be2719f4516676755b69d8a707b8/kewabexowumijo.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/e7m6gm88t35i9qqfulduf8qb8b/95602148892.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/cbb07319a6596b48861fe166eb20bc2e/zofakog.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/64833491039.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/5o90n1hgsne9t25r5ujk0nfdkb/tiramuwajixugu.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce51b0ed45---54454431370.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/hgh61rufk9775p4sv297k88p82/temaze.pdfIn PDF document text
    • http://www.asslar.de/downloads/puwulijuzowowaluxu.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/c1cbe837a44a26e841bfa279eb2924b0/zonokazunelini.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/5ff3f3e1a2a914a295b2bc81d58075f6/kuvorozatidozizur.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/46f2ca5db2f50dcb23b84e08a382e262/65666347661.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16079bd20e7e82---29942342850.pdfIn 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/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=morning+alarm+sound+effect+freePDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d3e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3E0 5344 bytes
SHA-256: c4898be5956a674e70440647bebf33d75fb712ac12fb3f030558e57e316e9427
font_01_sfnt_off0000e608.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE608 10148 bytes
SHA-256: dc33f0f7393e7eca6c209cad4c70ea128f33efb4b224df7fb1f59b3bb7fd8347