Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbbf8137f1d13782…

MALICIOUS

PDF

96.6 KB Created: 2021-06-27 11:43:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 9f78fa5370530042a741cf80dcd78d7b SHA-1: 7472ac409aabcb75086fac5ddd95e00de5d8caa6 SHA-256: cbbf8137f1d13782f32e6157ba5f6108d93829812c0d9990577c24232cbef41e
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories, suggesting a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and unreadable, preventing a deeper analysis of its specific pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607e78e057ea7---44191709393.pdf In PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/3992ee7f3168c52914bcf9f8bbd9af98/39448229744.pdfIn PDF document text
    • http://postelezmasivu-brno.com/ckfinder/userfiles/files/xikirototajimaderixedo.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/90gear0idebmdsuv0o1gtfinop/89864172286.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbd07d4937---belulitiragogerijuwine.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/24799481314.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e413b99ff6---18540142724.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/a46c4c14cc9b77565b7efa91ab3df75f/73922372063.pdfIn PDF document text
    • http://best-infosystems.com/userfiles/file/notesolisidodizatinobepu.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/o35g61sadt14us5qssk7rsl8r2/wofulikilo.pdfIn PDF document text
    • http://coffee33.ru/archive/file/53776740003.pdfIn PDF document text
    • https://medprobr.com.br/wp-content/plugins/super-forms/uploads/php/files/f77103212f8addbe9603a85ef055052b/lajuwesozameseduzojok.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cef533461f0---xixogofozo.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085f2b111e36---39459315304.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/84644348818.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160987164b490c---93202988424.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/c2b13f8d2b08b8e44491f25530a8b265/zipotot.pdfIn PDF document text
    • https://nhadatonline24h.com/Images_upload/files/binonezapopigozen.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa963820a4---17899086057.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/t6kou52j4b5oifd32b847i7hcf/53480351924.pdfIn PDF document text
    • http://davisfolk.net/clients/1/1f/1f1070e31f35868a9a13f38ee7dc887f/File/bokakezotonutuvotifodefin.pdfIn PDF document text
    • http://karunb.com/UpLoads/files/vijerisozetorukadexigexob.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/babojofuxodiraxijuf.pdfIn PDF document text
    • https://tonitomov.com/picture/file/73076663680.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=find+the+mean+median+mode+and+rangePDF 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_off00011538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11538 18624 bytes
SHA-256: 72f62a55d3a4367e0de92af63a1408566c73d262497c7f65c02a394ad3e2d90c
font_01_sfnt_off00014599.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14599 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015db0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DB0 10460 bytes
SHA-256: 16d9fc9d627e8722c8b389ee675f457fe41d9f23ebe65d5c9848cbe228f7f9e3