Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c79213fd3e97d1…

MALICIOUS

PDF

83.2 KB Created: 2021-09-07 12:03:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 102e269d53383038b101aa7945d5141f SHA-1: c0a71af3389891a22a9337729d189833a4620854 SHA-256: 81c79213fd3e97d1507604b06e9617170bd094a6bfa462c289a57f7260d9e82b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://oteaexpert.fr/cite_imgs/file/kadugisu.pdf In PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/ridusobulag.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/krr55fap9m4rht10h14bdqelkc/gafozovivulokipu.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c33346ac38---fojolenowexewov.pdfIn PDF document text
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b0352eb12---51332378073.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/bn1k8rju95j5pdj7c8jb6uu6b6/vopebanofedixizusuvevirut.pdfIn PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20210703021301.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16121a966717db---wewukifuvoja.pdfIn PDF document text
    • http://liqaa-lb.com/files/userfiles/files/35613974741.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/55125112016.pdfIn PDF document text
    • http://hotelstrack.com/bot/ckfinder/uf/files/gurutubunonaren.pdfIn PDF document text
    • http://mvclassof1990.com/clients/8/8c/8ca0ba2c7a07c5cd1f21f9fc323c16c5/File/tojex.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/06207qerco068f6616a662o10g/zipadamakakukivatiguja.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f60b503566---jefiko.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/pevubejofamelugo.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/8bc26a92d5ac3cc97c50cdda61194651/jelitirazu.pdfIn PDF document text
    • http://hyderabadibiryanicorner.com/admin/images/file/68931358446.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/93731093474.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/saravorawi.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c253c5a3bab---pokomopomureponinasumib.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/31647817732.pdfIn PDF document text
    • https://bluebeakbranding.com/wp-content/plugins/super-forms/uploads/php/files/084d57aa4e4c0b9d80715a3e405cc229/zimebobodebof.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/41366222116.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=past+simple+vs+present+perfect+pdf+exercisesPDF 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_off0000dd8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8F 18688 bytes
SHA-256: 482129982b5d68411c04d54bf66c46bfe90da3534ec548af87aba2d5fd25cc10
font_01_sfnt_off00010dc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC5 10832 bytes
SHA-256: e781ea2ae849165cf717dcea1ea7034dd05f39a40d8e2772549fff54208315c0
font_02_sfnt_off000126c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1