Malicious PDF — malware analysis report

Static analysis result for SHA-256 c94a84a87ebdfb8a…

MALICIOUS

PDF

97.1 KB Created: 2021-09-17 10:46:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8d454f07a087f90ac5b12a503015d539 SHA-1: 32a4011154a7d18d2a742338a2c1863f68bfc697 SHA-256: c94a84a87ebdfb8a9c44109b4ecf33c9c373eb20a782a09cc66d1f2678a132ed
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious documents designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://ketchas.ru/uplcv?utm_term=how+to+save+writing+on+a+pdf PDF link annotation
    • https://bleikss.com/userfiles/file/56252658921.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614410c089500---mudubuvebin.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/wukinozasejel.pdfIn PDF document text
    • https://huangs.tw/uploads/files/202109021019331138.pdfIn PDF document text
    • https://pinpointfeedtech.com/ckfinder/userfiles/files/namiwifezefov.pdfIn PDF document text
    • https://greenlakepaint.com/ckfinder/userfiles/files/zixijikarowunu.pdfIn PDF document text
    • https://congnghiepxd204.vn/upload/files/zemiserowukaruladugasowam.pdfIn PDF document text
    • http://kartelabasligi.com/images_upload/files/14821638817.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/ketunopewinaga.pdfIn PDF document text
    • http://enjoybowlramenandpoke.com/uploads/files/78771271289.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/bosilukevipoluza.pdfIn PDF document text
    • http://sky1981.com/asset/uploads/files/davobun.pdfIn PDF document text
    • http://unite-chem.cn/upload/files/84053740028.pdfIn PDF document text
    • http://studiochiodo.eu/userfiles/files/22910505877.pdfIn PDF document text
    • http://interiorconsignments.com/media/file/rurukigugaki.pdfIn PDF document text
    • http://www.oiseaubleu-promo.fr/userfiles/file/53950916685.pdfIn PDF document text
    • http://avalon-essenzen.at/userfiles/file/zixoxojodaruluduvugit.pdfIn PDF document text
    • https://lidiyageorgieva.com/ckfinder/userfiles/files/wogeratupexodapib.pdfIn PDF document text
    • https://edarky.net/data/file/bizebufibotex.pdfIn PDF document text
    • https://duhocblueocean.vn/ckfinder/userfiles/files/35730028673.pdfIn PDF document text
    • http://infiniti.e-library.tw/uploads/files/69614123803.pdfIn PDF document text
    • https://fabriziochessa.it/userfiles/file/jixijase.pdfIn PDF document text
    • http://mbeautyconcept.com/upload/content_images/file/96134319862.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/5670898355.pdfIn PDF document text
    • http://radyoislam.com/resimler/files/54942934997.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_off00011229.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11229 19916 bytes
SHA-256: 98eaddaf9b8fd52f5692288ae44a05a267b37055e020da61c6ad458bd158761e
font_01_sfnt_off000145c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015ddb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DDB 10768 bytes
SHA-256: e83ee5d0f8612607ed0227eac32c04e2ca6d42eebcdd22c5043cd7828367e144