Malicious PDF — malware analysis report

Static analysis result for SHA-256 87527fc489d17c79…

MALICIOUS

PDF

69.4 KB Created: 2021-10-01 06:58:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5990a3b71ec328f6338e408e2b9541ea SHA-1: f468cd6747a512b7457ca544a89a2f3d6dde2679 SHA-256: 87527fc489d17c79330078166ba557bfb4894ac7ede8267435f21fcb9dac47c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that form a link farm, with some pointing to compromised WordPress sites. The primary function appears to be redirecting users to external sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 https://oncallanatomist.org/ckfinder/userfiles/files/76427785268.pdf In PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/7e297c44ootdk0c68vrr9rj2s9/57859275544.pdfIn PDF document text
    • http://erdemlerkoleji.com/resimler/files/tezegupigavefopas.pdfIn PDF document text
    • http://intertribo.sk/files/fozisilejukipawexikenuz.pdfIn PDF document text
    • https://aprenda-atdi.com/uploads/files/fadixamukabuloba.pdfIn PDF document text
    • http://chizclean.ru/files/fck/file/88275042200.pdfIn PDF document text
    • http://sbstroy53.ru/img/files/jutejawazivo.pdfIn PDF document text
    • http://waypl.pl/upload/File/13722435377.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/webeganoliw.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/waxujitafisanigopiro.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/18796161056.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16152656e67161---nituwumutapamojadugurokiz.pdfIn PDF document text
    • http://tksvolga.ru/userfiles/file/javiwokewirusifo.pdfIn PDF document text
    • http://retrievers.su/ckfinder/userfiles/files/30771586448.pdfIn PDF document text
    • https://grupo-kayros.com/userfiles/file/41877967042.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/7a721d10fc05b406a2cf5307c1594fd8/26487877439.pdfIn PDF document text
    • http://dongduong.net/Images_upload/files/wuxorakeras.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/zizofamiwupam.pdfIn PDF document text
    • http://thsport.dk/userfiles/file/58302890045.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16140255d17abd---27036619269.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=real+boxing+2+rocky+apkPDF 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_off0000aeb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEB1 15856 bytes
SHA-256: d3859e3de78066f0afd09bb26d566de28d6fb682378ae40741608a5d3285ece9
font_01_sfnt_off0000d6e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF00 10896 bytes
SHA-256: c05b8605f700d72d14c7a257fcfcb112ede9639d4f5cc6524bc1e2007e92b627