Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ddd655a41bab25…

MALICIOUS

PDF

80.8 KB Created: 2021-09-06 01:47:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 18280f4e7f31947490559607c84ed2f6 SHA-1: 0f62ad35b38222cab913bbc0954e95581c5d214a SHA-256: 88ddd655a41bab25619df72aeb31c12af62452a15b3dfc6fc5c25f6b87c70ec2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external PDF files hosted on various domains, many of which are flagged as compromised CMS upload storage or part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were directly extracted, the structure and embedded URLs suggest a lure to download malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://asi-filter.pl/files/file/61453809648.pdf In PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16130e66720932---dariri.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/160baca122cce9---87995580649.pdfIn PDF document text
    • https://samoinstitute.mn/uploads/assets/file/mubekoranega.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/98068728148.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/11558180115.pdfIn PDF document text
    • http://packturf.fr/files/94315620130.pdfIn PDF document text
    • http://dierenwinkelindex.nl/images/uploads/sorezatorinulonor.pdfIn PDF document text
    • http://usmleworkout.com/files/file/kefebugemilasifoduvez.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/dixujapedek.pdfIn PDF document text
    • http://gzperson.com/uploadfile/files/jilejuv.pdfIn PDF document text
    • http://nkland.org/userfiles/files/zigajuverabevabakubusep.pdfIn PDF document text
    • http://csc025.com/userfiles/file/20210730023016_8i0fol.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/vupifowosaralamikobizatij.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610e748e790d5---46952385423.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/11dju4bofv74lm29rc747pgfc4/xododafoledilut.pdfIn PDF document text
    • http://upoart.com/ckfinder/userfiles/files/dizefuvunuxiwifam.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/c14b28a9b11e57ba732b6cbd024b40ea/befowadipipuwe.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/a381b8f671903703a6b5cf6ecd432b4c/45692437349.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/sugazim.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/c60a53e03e94273621f873dae91001b3/tojosamol.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/77096664449.pdfIn PDF document text
    • https://talaa-obour.com/webmisr/uploadwebmisr/file/gipib.pdfIn PDF document text
    • http://fairview68.org/clients/c/ca/ca24e3df3ff7fa9b839de6c08aba9959/File/mawuge.pdfIn PDF document text
    • http://bangladeshceramicsociety.com/uploads/editor/files/gelelurarifiwovazan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=convert+word+to+pdf+free+download+for+windows+7PDF 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_off0000d8f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8F2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF104 16748 bytes
SHA-256: c6ba0983ed25df23c2b50b89d668a331ef8b3b08f4151ef1362756abde213d65
font_02_sfnt_off00011c64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C64 10724 bytes
SHA-256: 1bca112d65abb34aa6d45f409e48180681a29720f19fbca30b162663deb32729