Malicious PDF — malware analysis report

Static analysis result for SHA-256 81200b0d7ba32917…

MALICIOUS

PDF

81.4 KB Created: 2021-09-12 11:11:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c73e2dc3dd60e7dea703890f5a4e472a SHA-1: 6af147cd3cb4e5db68c8eb71f8fa02a31a3ce86c SHA-256: 81200b0d7ba329177d7b11d9c778f4d8c7d9ed7f2e1cd6148ec8d1ec1e1fcaec
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically identified as a phishing trojan by ClamAV. The document functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely intended to redirect users to malicious sites. No scripts were extracted from this sample, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://manualismedicina.hu/fileok/file/40360378021.pdf In PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161394b6486a3d---6646619555.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/161371467e9215---sajibikad.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/6e141bc6fed1df17a4ed10ac041a7ba9/rizuwesutoveponiradunilul.pdfIn PDF document text
    • http://moonlightmontessori.com/upload/files/ginolenoxijelezi.pdfIn PDF document text
    • http://trieuduong.com/images/Download/fevewiwefe.pdfIn PDF document text
    • http://home-plast.ru/foto/files/88259286235.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138dd92687ec---63686803421.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/lewuweraluwafaberimave.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/gilifadobodikezibolatu.pdfIn PDF document text
    • https://aakritidigitals.com/userfiles/files/82863049407.pdfIn PDF document text
    • http://stl-hk.net/userfiles/jenudogusomama.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/tutesezebebubop.pdfIn PDF document text
    • https://mzr-avocats.com/buddha/ckfinder/userfiles/files/96451480001.pdfIn PDF document text
    • http://rainternacional.com/userfiles/file/14881825512.pdfIn PDF document text
    • http://allseasonsart.com/uploads/fck_uploads/file/kewatezozikejufidew.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/45709783921.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/81180082008.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/jinukixugunobifamo.pdfIn PDF document text
    • http://wsm.hk/images/uploadfiles/file/74520026911.pdfIn PDF document text
    • https://dgssu.com/upfolder/e/files/20210903200147.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/89108547245.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=nexspy+mod+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_off0000db10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB10 10396 bytes
SHA-256: fbd04373d227587731948fb7169410aff76635db353c346832f2b5bbfa98857a
font_01_sfnt_off0000f2ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2AE 17604 bytes
SHA-256: e9125b12aa969947beed5c87370442d28bdc41205ef11fdd2775192639c27aa8
font_02_sfnt_off00012099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12099 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1