Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f3b77a8bec3a2fd…

MALICIOUS

PDF

68.6 KB Created: 2021-09-29 13:32:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a5ec7f432ba88f5c3185058dba62e62a SHA-1: 83aa0070d194e99382ac5fbbbe15e0c07d57b49b SHA-256: 5f3b77a8bec3a2fdbde9302e9850a244fc5bc4a1ccae2059127d215e271d0fa3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. Multiple external URLs are embedded, suggesting a phishing or malware distribution attempt. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://coretry.ru/uplcv?utm_term=video+game+music+samples PDF link annotation
    • http://fabriziocar.it/userfiles/files/97092111436.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/70806250838.pdfIn PDF document text
    • http://ambvetbrashersclavoghisu.eu/userfiles/files/fumupopokosigezukizizeguz.pdfIn PDF document text
    • http://abwgulfport.com/uploads/files/mibovewaluromovederibu.pdfIn PDF document text
    • http://oilspecchem.com/files/nezapuj.pdfIn PDF document text
    • http://apsara.ru/userfiles/file/44388162467.pdfIn PDF document text
    • http://fsanaq.com/upload/file/210905032300728252fopgum5dhg45.pdfIn PDF document text
    • http://hyswimpool.com/userfiles/40153223989.pdfIn PDF document text
    • https://webmenuplus.com/images/file/rasasuruvogetesokawulos.pdfIn PDF document text
    • http://ruresept.ru/files/file/futidapup.pdfIn PDF document text
    • http://hzaidele.com/images/upload/File/wekerijevukuzoximisojojeg.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/98815673676.pdfIn PDF document text
    • https://topupdana.com/contents/files/tebenubuxovo.pdfIn PDF document text
    • http://trieuduong.com/images/Download/tupemulugurutowovuke.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/75551401060.pdfIn PDF document text
    • http://dunajecbiala.pl/upload/File/jemozoxaliraribumi.pdfIn PDF document text
    • http://www.rsvpcatering-ar.com/files/imagesfile/22107918772.pdfIn PDF document text
    • https://segurodegranizo.ar/noticias/fckeditor/file/linagixasunev.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/kipot.pdfIn PDF document text
    • http://4226080.kad.tw/kads/ckfinder/userfiles/files/jojowuzojilomof.pdfIn PDF document text
    • https://suprastoc.ro/userfiles/file/26751398544.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fb043b981d---49416481672.pdfIn PDF document text
    • https://lenaoyunlar.net/calisma2/files/uploads/kejumomen.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_off0000adb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c5c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5C7 10624 bytes
SHA-256: d07ae971eb027c5bad145dc9d31913743f7183737c7a01793003af1313581318
font_02_sfnt_off0000ddde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDE 15524 bytes
SHA-256: c7e54b4bf6dbbcb2b041263d16cad7260bde3bc1bcc5406542f508b826d40671