Malicious PDF — malware analysis report

Static analysis result for SHA-256 b438307a6f43ca6f…

MALICIOUS

PDF

81.2 KB Created: 2021-09-15 17:46:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 568c6ee6066c192f64c853ffd7dd5050 SHA-1: ead5f02b76cf2fa149a8967cf3604a2a15e7d0ad SHA-256: b438307a6f43ca6fa167461c55e5fac4a182067b98bf167ce135412e3ac9b874
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, characteristic of a link farm designed to obscure the ultimate destination. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic and the high number of distinct hosts strongly suggest a phishing or malware distribution attempt. While no scripts were explicitly extracted, the ML classifier and ClamAV detection indicate malicious intent, likely involving the exploitation of PDF vulnerabilities or the delivery of malicious content via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://jazykovytabor.topenglish.sk/app/webroot/gallery/files/wijomezezirunipaduzuwe.pdf In PDF document text
    • http://osteriailgalloelinnamorata.com/userfiles/files/39394297193.pdfIn PDF document text
    • http://3q1p.com/upload/file/210905112517259501ou2uv2z9ty60.pdfIn PDF document text
    • http://jca-t.com/fck_image/file/22307662386.pdfIn PDF document text
    • http://vakoplus.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/41131937763.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210901110111.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613912c6d4745---35329273403.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/91235687869.pdfIn PDF document text
    • http://bowie.abwingsmd.com/uploads/files/39031859242.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/repotaxeburepibapi.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/lewereramobikiju.pdfIn PDF document text
    • http://vendsol.com/userfiles/file/rejagi.pdfIn PDF document text
    • http://cross-winds.in/upload/contents/images/images/fagukufira.pdfIn PDF document text
    • http://systempro.kr/userData/board/file/22988613144.pdfIn PDF document text
    • http://jimsclub.net/new/board/img_tinfo/file/20210913023056.pdfIn PDF document text
    • https://tunguoilon.tunhua.vn/ipp/images/uploads/files/68267955048.pdfIn PDF document text
    • http://pfmconsulting.org/survey/userfiles/files/leguzulurapobutetubu.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/16132ecca565fa---nefovigapuxe.pdfIn PDF document text
    • http://stylowa-pss.pl/userfiles/file/linupeginirenusagiz.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/177830711.pdfIn PDF document text
    • http://tbeaindia.com/userfiles/file/16845706871.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/kurasosuz.pdfIn PDF document text
    • http://floral-design-lindgens.de/userfiles/file/teligarerogeli.pdfIn PDF document text
    • http://yucehukuk.com/resimler/files/65663812685.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/negodaweriz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=asbo+gta+5PDF 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_off0000d9f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F2 10064 bytes
SHA-256: a6775a5c85b26dcea59a1f156ab79ba30fa42fe436604b5729d1577957991526
font_01_sfnt_off0000f093.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF093 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A5 17916 bytes
SHA-256: 678d43ba0a2870ed086071f8ffa2f06d62cb714caccc3067f1c33d2e3fd195f7