Malicious PDF — malware analysis report

Static analysis result for SHA-256 8973cdff04bbf757…

MALICIOUS

PDF

70.6 KB Created: 2021-09-22 09:18:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: cd58791542a1c03b877b71c7c10e8837 SHA-1: def0b9c9f54456ada3da86f2acffaa88b9462a07 SHA-256: 8973cdff04bbf75716dba54832433cfb84635ee0e3568cea16cb8fdc27fa535f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links suggest it's designed to lure users into clicking through to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://dunakeszi.varosom.hu/userfiles/files/52764398045.pdf In PDF document text
    • https://okud-istra.hr/userfiles/file/tekajanusatugita.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210903131252.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613b97746d14a---69908454495.pdfIn PDF document text
    • https://ismet.com.br/ckfinder/userfiles/files/13419888934.pdfIn PDF document text
    • https://lmcmanager.com/ckfinder/userfiles/files/8972345620.pdfIn PDF document text
    • http://chineseclothingonline.net/File/95241333561.pdfIn PDF document text
    • http://farmaciafoglia.eu/userfiles/files/tukame.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161376ddd45aac---82066588456.pdfIn PDF document text
    • http://nhakhoasaigonkimcuong.com/uploads/images/files/38593933059.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/36934849427.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/161496f462cc02---vigusunurivapimuwoz.pdfIn PDF document text
    • http://flairpens.ru/uploads/files/kesokamuduserukaxi.pdfIn PDF document text
    • https://adrfarysz.pl/userfiles/file/19174561805.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109022315426994.pdfIn PDF document text
    • https://fceresources.com/ckfinder/userfiles/files/67310204317.pdfIn PDF document text
    • http://ntouioc.ntou.edu.tw/ckfinder/userfiles/files/xenowomadeniwarovesugol.pdfIn PDF document text
    • https://cafemocion.com/userfiles/file/62727649932.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ac9b2b1580---daladuwivevetepofi.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/lutowek.pdfIn PDF document text
    • https://clicksnepal.grnca.org/img/files/files/filubanufojabuzetufaxil.pdfIn PDF document text
    • http://fxlcd.com/upload/file/10165308980.pdfIn PDF document text
    • http://ymmicro.com/files/files/10345993019.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090223052320.pdfIn PDF document text
    • http://spad.kr/userData/ebizro_board/file/99451413472.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=crash+bandicoot+psx+iso+downloadPDF 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_off0000b208.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB208 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA1A 16764 bytes
SHA-256: 967534c725d5bfbc944870b04fe4312a0ad3b8fdc3d30be9390332b0cc69fb4a
font_02_sfnt_off0000f3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FA 10840 bytes
SHA-256: e96a962bb02a24874b0b00b92fa3f8c0d7d41e1fb34155bfc0e484d0523aff0b