Malicious PDF — malware analysis report

Static analysis result for SHA-256 a127d693058de2b3…

MALICIOUS

PDF

85.1 KB Created: 2021-09-15 14:49:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3bec8e11ccaed826401fa633d0d76ce1 SHA-1: 11c6852509b52f969424c86ff1e928fc07d46e24 SHA-256: a127d693058de2b33d1e7594f42e89aa0e52549b6d7266de44b221c4b5b53d7c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The file is identified as a malicious PDF by ML classifiers and ClamAV. It contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting domains, likely intended to redirect users to phishing sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a tactic to obscure the true destination by using multiple distinct hosts with single links each. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://smidgel.ru/uplcv?utm_term=grammar+pdf+download PDF link annotation
    • http://nesemlak.com/test/images/uploads/files/18872874640.pdfIn PDF document text
    • http://meuble-tunisie.com/userfiles/file/90491325807.pdfIn PDF document text
    • https://abicecream.ru/ckfinder/userfiles/files/jipuxoturimegojid.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109051718105985.pdfIn PDF document text
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/teniwa.pdfIn PDF document text
    • http://aci-immobilier-douai.fr/userfiles/files/pifufolomataxa.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140bc9956374---dilazuvuvazu.pdfIn PDF document text
    • http://katela.net/userData/board/file/69335085881.pdfIn PDF document text
    • http://honeystraw.com/uploadfiles/file/15837997759.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/didilegoduvozufisofovimu.pdfIn PDF document text
    • http://arisutour.com/ckupload/files/kezinanato.pdfIn PDF document text
    • http://chinawin-consult.com/userfiles/xepum.pdfIn PDF document text
    • http://vanxuantravel.com/upload/files/69965748980.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/b21cd9edb0de276522dbcd1132dc2b5b/78000645130.pdfIn PDF document text
    • https://samsungklima.net/upload/ckfinder/files/77895263542.pdfIn PDF document text
    • https://ipic.vn/userfiles/file/movimilikituzeralatu.pdfIn PDF document text
    • http://www.gdchgs.com/admin/img/files/99432251935.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/jizepolubimud.pdfIn PDF document text
    • http://garderoba.sk/images/_file/bowijemediwez.pdfIn PDF document text
    • http://markjfox.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/36183827140.pdfIn PDF document text
    • https://ecpa.fr/uploaded/file/86630522624.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16137a83a0c58e---tozex.pdfIn PDF document text
    • http://mlight.cz/archiv/file/36446359352.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_off0000e7fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010015.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10015 10292 bytes
SHA-256: 9d99d582f3fca6b6cdaeff56cbd7e35092e75bb19d3d0a085f578e17b6048ad0
font_02_sfnt_off0001173d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1173D 18336 bytes
SHA-256: 9b58964446ef8d6a35f14ced7e996af46a6bc6e2c2b10164845d37f1d5bdd4fc