Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef991668ad31e894…

MALICIOUS

PDF

70.9 KB Created: 2021-09-29 08:16:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 50c47c78219a6ceb5048c1097225b384 SHA-1: 54a4d3c65842f4b62d78a293eaa8a4e23e3c64f1 SHA-256: ef991668ad31e8944fe3a0e1813185c6319e7c5244ae06d59549934eddf8535e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading further malware or engaging in phishing activities. No scripts were extracted, but the PDF structure and embedded URIs are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://inwebjor.ru/uplcv?utm_term=group+theory+books+pdf PDF link annotation
    • http://kes.org/upload/editor/files/14984556789.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/tebbio5g2j8hee9201rg3dmhg3/23081571607.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/bugimatixujaduxavototo.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5f1191840---86008010823.pdfIn PDF document text
    • https://wecareprogram.org/images/file/55687497007.pdfIn PDF document text
    • http://perilatomsk.ru/ckfinder/userfiles/files/22242021104.pdfIn PDF document text
    • http://tartak-monis.pl/tartak/images/file/94238619038.pdfIn PDF document text
    • https://anhhuynoithat.com/asset/files/gogokixi.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/vavazufafirebixosokumor.pdfIn PDF document text
    • http://laserinnsbruck.com/static/monofemabebabuzexide.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16138282cba9bb---94534664715.pdfIn PDF document text
    • http://whatifitspossible.com/ckfinder/userfiles/files/63775030995.pdfIn PDF document text
    • http://avatars.ru/userfiles/file/vitawos.pdfIn PDF document text
    • https://emenu.hu/editor_up/batogokesaledumesuxabi.pdfIn PDF document text
    • http://toflight.mobi/attachment/ckeditor/files/91c7a25e96e2201d8b4a5b7a001c47a2.pdfIn PDF document text
    • http://brlairport.com/images/file/butizanawipojovabefukedo.pdfIn PDF document text
    • http://xmzhj.com/UserFiles/file/84767504003.pdfIn PDF document text
    • http://ticaproduce.com/ckfinder/userfiles/files/veleparotuxizopidenaw.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/jadevoxipezesarovot.pdfIn PDF document text
    • http://nikacarpet.com/My_Project/Hamishe_bahar/ahar_img/files/3021878699.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/813607957.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-27/20210927054416993396.pdfIn PDF document text
    • http://suncitygroup.ir/basefile/suncitygroupir/files/fobiwarowakifolupidu.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_off0000b25f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB25F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA76 10676 bytes
SHA-256: e5e1c45412bfd08b7384d6f9f1b01f2a4d980ae2227813a00c88df979f8f1da7
font_02_sfnt_off0000e2f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F2 16668 bytes
SHA-256: e7cc2388920098d8b5054471ae32ea9f724f3de96af14981437b57c2c5743f3d