Malicious PDF — malware analysis report

Static analysis result for SHA-256 13939a5d31d76910…

MALICIOUS

PDF

79.6 KB Created: 2021-09-13 04:49:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2298d651a73b13b0cb905e3de828c67c SHA-1: f138a9e5a943be8bf86a22c8961c1c6efcbf7fdb SHA-256: 13939a5d31d76910947ad7c8092cfaa48fa3229376012642f1a3ff8dd81b85ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous links suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://coretry.ru/uplcv?utm_term=1+cm+grid+paper+word+document PDF link annotation
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/5932453801.pdfIn PDF document text
    • http://jingkangchem.com/upload/files/puvubilogizoruxagugepigi.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210907192552.pdfIn PDF document text
    • http://szjglaw.com/uploadfile/file/2021090516461473499.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/xedivedobakulefuvolikatun.pdfIn PDF document text
    • http://hbaoge.com/upload/files/55889702754.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/raravune.pdfIn PDF document text
    • http://gmart-express.com/demo/uploadpic/file/kegulenuvopinogiruju.pdfIn PDF document text
    • http://c2r.su/uploadfiles/file/2021090410534773499.pdfIn PDF document text
    • http://jsdarvin.com/files/41710541029.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/615ebc16f9d75202cb7205e8afb0b6e6/rawopawudunesinubipuvije.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16131651a1010e---2862666921.pdfIn PDF document text
    • http://seasonsblinds.com/uploads/ckfinder/userfiles/files/22195859770.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/89761919279.pdfIn PDF document text
    • http://generaldistco.com/images/file/81315654181.pdfIn PDF document text
    • http://quaint-house.com/images/blog/file/juxajitojoxusumalusotuza.pdfIn PDF document text
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/54461968046.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba3859a82c---zaxutixiridatimote.pdfIn PDF document text
    • http://labuchedeberce.fr/userfiles/file/11695511311.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/22563291152.pdfIn PDF document text
    • http://nordicwalkingturak.hu/_user/file/sajemokodipipeki.pdfIn PDF document text
    • https://psychologgia.pl/Upload/file/39480813464.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_off0000d5be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000edd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD5 10784 bytes
SHA-256: fd46b63d71b5722bfc67b563f8079f087724faf27acdf5f29653d81be8293d46
font_02_sfnt_off0001067f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067F 16576 bytes
SHA-256: e6826053ca15886ce600f772c18a49f138479df7cba8acd813054ed60bdfc99d