Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2613ce870cdf059…

MALICIOUS

PDF

72.2 KB Created: 2021-09-18 01:18:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2a36673f10aed8b77e22b017ff7efa0c SHA-1: 3bdccf302ed5de3e164c26bea3156776bf873130 SHA-256: a2613ce870cdf05917b7076b48e2238e47a7e3d80652d4ef79b6e1d47b5fc688
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to obscure the ultimate destination. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate effort to create a network of redirecting links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://nedirajtebosnu.net/userfiles/file/lugivalifobakima.pdf In PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/tafik.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/2s6o02rjtkbb90s64mhjlmmbs2/37056397130.pdfIn PDF document text
    • http://ramenhajimetustin.com/uploads/files/15194100607.pdfIn PDF document text
    • http://ohmytour.kr/FileData/ckfinder/files/20210916_BC938764C0F67C87.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/886def9457d485b48caf9693d37a1e0a/fiwojareribaf.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/xatuxixibiwijafagoxoti.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd7203c25c---kemegoxotuven.pdfIn PDF document text
    • http://huerural.com/uploads/image/files/jebovimogabegaveto.pdfIn PDF document text
    • http://cssh.es/img/file/ziposefidumur.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/848fce979f5fd05d92832da0ec3506a9/26489292795.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141a6a951519---65740273854.pdfIn PDF document text
    • http://ibrahimabuomira.com/ckeditor/ckfinder/userfiles/files/55101716518.pdfIn PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/33433132961.pdfIn PDF document text
    • https://conexus-study-abroad-travel.com/ckfinder/userfiles/file/21571390432.pdfIn PDF document text
    • http://actinq.nl/upload/file/gamaxoxaragafufamasoraget.pdfIn PDF document text
    • https://atlas-consulting.ro/fckeditor/fisiere/file/pawafinuponijuwidudo.pdfIn PDF document text
    • http://app0.linkeo.it/ckfinder/userfiles/files/97072339002.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613540fda0d28---86538424109.pdfIn PDF document text
    • http://levant-tekstil.com/other_files/File/29313318266.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/32251467660.pdfIn PDF document text
    • http://woodlandhills.ilovepokebar.com/uploads/files/fafesoxasixowisuxig.pdfIn PDF document text
    • http://www.kyousei-fukushi.or.jp/system/ckfinder/userfiles/files/89071522708.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/bumapirinukakinorutu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=connect+android+phone+to+pcPDF 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_off0000b991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB991 16456 bytes
SHA-256: f83ac8c1c1a9be6b0555094abcf7cad53af89b9a315490a481285d7a65540245
font_01_sfnt_off0000e35d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE35D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB74 10428 bytes
SHA-256: 6057b341c6b30a49695ca06c9a88388e6d934f92a87fc9c9d3e5db2d2a1c6bae