Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b533c755d408a81…

MALICIOUS

PDF

69.2 KB Created: 2021-09-28 10:12:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e566b0d5c5b386a00c056967acb702b1 SHA-1: a739042370dc1c7f64c92cd367401e799a9cec08 SHA-256: 9b533c755d408a81b1a6551c00b0d6f966f055d327d087f9cf84ef1ab121e9af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://synerhu.ru/uplcv?utm_term=play+install+referrer PDF link annotation
    • http://tunesistudio.eu/userfiles/files/33637151497.pdfIn PDF document text
    • http://praguetransfer.com/files/file/32086252870.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/72378829005.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/vapujuga.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/vevup.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16150eca5c7249---82851604316.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/zumezijibarote.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/d8e3ab663f92be6bd31b3ca9375b5f7b/77497312370.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/36513844622.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/vetirupen.pdfIn PDF document text
    • http://drtamerturan.com/file/93625340023.pdfIn PDF document text
    • https://giverny-bkk.com/upload/files/92461085712.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/segufenerekuxotazu.pdfIn PDF document text
    • https://nepalipublisher.com/ckfinder/userfiles/files/gufot.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/f411a823d0f738ad862c4be850da4f44/tenatadaxisag.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/65713799489.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/titekovoke.pdfIn PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109071747586411.pdfIn PDF document text
    • http://gld-lining.com/user_img/files/45709898354.pdfIn PDF document text
    • https://www.natursany.com/ckfinder/userfiles/files/silaloposikodakubiwufe.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/79967347035.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/1468606642.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161471bc9066a3---23581518696.pdfIn PDF document text
    • https://sieuthigo.vn/upload/ck/files/rosud.pdfIn PDF document text
    • 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_off0000aee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEE0 10200 bytes
SHA-256: 36bbd27deefe712b18060be4724e9f9cc71de3f0a09a48a645a7645af8f108cb
font_01_sfnt_off0000c5df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5DF 15652 bytes
SHA-256: 33273b0a7209388339cd7d87fabdc9f664b6d01882ea2cb1c48851bd24a3974b
font_02_sfnt_off0000edad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDAD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1