Malicious PDF — malware analysis report

Static analysis result for SHA-256 692c1662043576e9…

MALICIOUS

PDF

76.8 KB Created: 2021-10-04 02:27:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9ae36ee24eaeb078097edcd76294c256 SHA-1: ad885e29b57bf31277c9c5a78d7a4c9d1e705270 SHA-256: 692c1662043576e94aeb0e54843b0238ccb4082111491b043dad1973e5929265
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to PDF files hosted on compromised websites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting and potentially SEO manipulation to distribute these linked files. The presence of multiple unknown PDF links suggests a campaign to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://year-c.com/upload_fck/file/2021-9-23/20210923043026628852.pdf In PDF document text
    • http://auroraenergyproject.it/userfiles/files/63342799425.pdfIn PDF document text
    • http://worshipedia.mobi/sites/default/files/file/69364372371.pdfIn PDF document text
    • http://www.wcd.com.tw/ezadmin/ckfinder/userfiles/files/52464730876.pdfIn PDF document text
    • https://global-brand.net/userfiles/files/xefixovaf.pdfIn PDF document text
    • https://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/gotaxobizofijolilosawoxuw.pdfIn PDF document text
    • http://seritour.com/rsm/files/palevemapegov.pdfIn PDF document text
    • http://controlsystemco.com/cache/fck_files/file/gokozer.pdfIn PDF document text
    • http://taihegas.com/filespath/files/20210925135928.pdfIn PDF document text
    • http://guitarenko.fr/img/files/xuwufedomitorupivupu.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/jpg0lho0032s0u4j8q9v1pah51/67378072531.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021090512090973499.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/cce5166cf684d779cba9c0eba5270f9f/45692027241.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcf149fad3---16823699515.pdfIn PDF document text
    • http://planbmedia.hu/files/14839506589.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613267ae277bd---sojof.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210917_021703.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/202110128232908.pdfIn PDF document text
    • https://segurodegranizo.ar/noticias/fckeditor/file/96508669458.pdfIn PDF document text
    • http://mcutech.net/files/74107827842.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-2/20210902155830843675.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=joseph+and+the+amazing+technicolor+dreamcoat+liverpoolPDF 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_off0000be99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE99 11080 bytes
SHA-256: 0c08e2fd56ba806fefa4e64858ddddcb5353513c1fb86cdcc3f8cace19507659
font_01_sfnt_off0000d819.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD819 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f02b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02B 20364 bytes
SHA-256: 03d2615f1873fc9c9c8786d936078a143916e03754cd7a9a9da5f9eace35daf2