Malicious PDF — malware analysis report

Static analysis result for SHA-256 4532a3adb44ad61a…

MALICIOUS

PDF

81.1 KB Created: 2021-09-17 01:04:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dd12dcac115cf801e16fca03973ec3b8 SHA-1: a05aa04ec6f128af4e4703285ba2a4acafc9d590 SHA-256: 4532a3adb44ad61a9a90aace71bce307e3dda24ac8c6d782adf7f73963f30c58
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to potentially disposable domains, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a pattern of using such domains. While no scripts were explicitly extracted, the nature of PDF malware often involves exploiting vulnerabilities or redirecting users, aligning with the identified techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://sartor.ru/upload/files/xavalepagunefadufazuvez.pdf In PDF document text
    • http://elementyzlaczne.pl/media/file/11286781444.pdfIn PDF document text
    • http://tachikawa-derma.biz/ckfinder/userfiles/files/ganoboxe.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/xolififeladotivomasad.pdfIn PDF document text
    • https://mamo-tato.ro/userfiles/file/zikelatajosedow.pdfIn PDF document text
    • http://consorzio-csa.it/userfiles/files/xipugevumowa.pdfIn PDF document text
    • http://imssp.by/data/images/fxeditor/file/57184631349.pdfIn PDF document text
    • http://reguitti-engineering.it/userfiles/files/vebadetekepuminutu.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/nowubimuv.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/36549393478.pdfIn PDF document text
    • http://fkjz.cn/upload/files/2021/09/202109110319577862.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd43294bed---33432087177.pdfIn PDF document text
    • http://www.horakgolf.cz/ckfinder/userfiles/files/dikefitefupijetopirora.pdfIn PDF document text
    • https://vayamcs.com/content_files/files/89713612855.pdfIn PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210901_4C5218DB0F45C687.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/48176500592.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/dusibexo.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/21727440480.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/65548406269.pdfIn PDF document text
    • http://k3projekt.pl/uploads/userfiles/files/kefetitugafosuxapukom.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/16385960859.pdfIn PDF document text
    • http://abnig.friendship-match.com/upload/files/37331706647.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=project+cars+go+for+androidPDF 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_off0000d738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD738 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF4A 18232 bytes
SHA-256: de488890d576a3b29c62a6d566dd47e43d8b1f342dc93f4f47d00ef948d0ce34
font_02_sfnt_off00011ea4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA4 10736 bytes
SHA-256: d3adbe07edb0608b8b89ba8936037da11de081c99e29f52a9de32a1cd8c3ded4