Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38d89148e387be8…

MALICIOUS

PDF

69.6 KB Created: 2021-09-24 16:46:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 98b4bbf5237099f8d613c9d19d347f37 SHA-1: d424e586e27b44aaa1531c4d8f5b7d7fe5b64c45 SHA-256: a38d89148e387be821fb61bd4720e120fb7b545e76272709c948a32a648ac9c0
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 CMS upload storage, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the embedded URLs and heuristic firings are sufficient to infer a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137ffbf00bfb---dexaxusatesanoxinutipi.pdf In PDF document text
    • http://lamardaegu.com/upfile/user/file/47414543168.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/77498256808.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/55853949873.pdfIn PDF document text
    • https://nadrozmerne-sklo.cz/uploads/mamugiwitanada.pdfIn PDF document text
    • http://etoprosto.ru/ckfinder/userfiles/files/18317070268.pdfIn PDF document text
    • http://rklatex.com/userfiles/file/77160389755.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/siviboju.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/jerudefumil.pdfIn PDF document text
    • http://foto-preiss.at/upload_files/files/sexaxevakegojotefexo.pdfIn PDF document text
    • http://dorrstrechy.cz/UserFiles/File/2656988203.pdfIn PDF document text
    • http://newshop.jp/archive/file/jasaxek.pdfIn PDF document text
    • https://leganordavigliana.com/uploads/file/batewisexojedukegilez.pdfIn PDF document text
    • http://hyunbulsa.org/~ewedd2/userfiles/file/wipopabunanoleti.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/f21b0ed9fe19fcfe399cbf17b2cab7ad/60398549606.pdfIn PDF document text
    • http://kondicionery-shodnya.ru/upload_picture/file/35521318005.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/bedutebo.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1613ebb52296e1---7961064325.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/liruxapi.pdfIn PDF document text
    • http://aias.pnu.ac.th/ckfinder/userfiles/files/poxejuzugetorenijiloli.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/eb0dbeacdb1d0890f0490590894a1b83/ralowolofo.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/099052da33b78baae1849f9f79d3d14e/57367989208.pdfIn PDF document text
    • http://nhagiatxanh.com/public/default/ckeditor/files/zewototuwato.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/xarokepezulorosubodid.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/4e7sufo574ejo05v67gh23gk3n/timox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=android+automation+with+pythonPDF 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_off0000b0b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0B1 15172 bytes
SHA-256: a6e539ef5986a489f2058bb54b69a1ad919895cf202c29f29dd5ecc01bdd1375
font_01_sfnt_off0000d6fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FB 10592 bytes
SHA-256: 1eb7f88286a2d868e647282b8c83732816d4432697c59c914ce28c41542d11af
font_02_sfnt_off0000ef04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1