Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b06fb2f6ae45dbc…

MALICIOUS

PDF

93.9 KB Created: 2021-09-15 12:52:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ea613d69f9bf4ccbf294bf9eed8bc490 SHA-1: 6ec82ae82e8a504b53ad86ceb949c76cad4322bf SHA-256: 3b06fb2f6ae45dbc1ccd2bdf39bb2b587bb6b634eb370ae77a63fbdfce34e3be
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristics and URLs suggest a lure to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://synerhu.ru/uplcv?utm_term=phrasal+verbs+esl+worksheet PDF link annotation
    • http://lltsg.com/uploadfile/file///2021090605482369.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/8a591f04d73605e8e044e4553fcd0f85/pafowilobejuxodajutu.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161413e169a141---lemokowefimi.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090303321527104.pdfIn PDF document text
    • https://thailonghoang.vn/upload/files/95708725527.pdfIn PDF document text
    • http://professional-tuner.at/uploaded/file/57268006856.pdfIn PDF document text
    • https://fetogram.com/images/upload/files/vizisewutasofunog.pdfIn PDF document text
    • http://85560891.com/upfolder/e/files/20210912122303.pdfIn PDF document text
    • http://ebus.cn/up_file/file/padosefoded.pdfIn PDF document text
    • http://allineers.netlovestories.com/upload/files/60732653702.pdfIn PDF document text
    • https://anakmeong.com/contents/files/vesaso.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/30242871147.pdfIn PDF document text
    • http://hrt-foto.hu/_user/file/senuzugemizotejedig.pdfIn PDF document text
    • https://cheeselicious.net/UserFiles/file/10393863328.pdfIn PDF document text
    • https://aksukartela.com/images_upload/files/86227000307.pdfIn PDF document text
    • https://bipalisdemo.dashindonesia.com/userfiles/files/65304489384.pdfIn PDF document text
    • https://qian-ho.com/upfiles/editor/files/sozanuwojisopajonoza.pdfIn PDF document text
    • https://matricula.arendic.cl/files/86763136577.pdfIn PDF document text
    • http://vidol.eu/userfiles/file/buvajoxi.pdfIn PDF document text
    • https://villadorottya.hu/uploads/frontend/files/96736135515.pdfIn PDF document text
    • http://bancasemecanino.com/userfiles/files/72534126770.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/2719715161f2985dc96cd95f9747d6e8/nezeginegatewesib.pdfIn PDF document text
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/nuzag.pdfIn PDF document text
    • 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_off0001071b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1071B 19584 bytes
SHA-256: 074bb675b650822577f1f6ed04274b8fb31881c54e581b41f09eca4eee6de25d
font_01_sfnt_off00013a4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A4B 10392 bytes
SHA-256: 49d7fa1076271cc4a0f4c95c005fa480a19fbd5cbc93cbcdaa02c1e4ab5b8939
font_02_sfnt_off00015215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15215 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1