Malicious PDF — malware analysis report

Static analysis result for SHA-256 a229327d0ffd43e6…

MALICIOUS

PDF

79.5 KB Created: 2021-09-06 12:36:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 537d69cd40cd5e3ff1aa6714fb28203f SHA-1: 3e01f6d7a7fd327ff0e25594d63b07e7f504eab5 SHA-256: a229327d0ffd43e6f82f2e88e3d864379390ebbcb3b2f69406227f2220617e93
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The `wkhtmltopdf` authoring application indicates it was likely generated programmatically for this purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://krisoc.ru/uplcv?utm_term=policing+in+south+africa+pdf PDF link annotation
    • http://ahcxdq.com/uploads/file/301820317258.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/52646042733.pdfIn PDF document text
    • https://invest.pl/userfiles/file/lasikoso.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16085fb26b650e---bedirinopipifakewegonim.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/a934c810b9665384781ad17471304156/kemagu.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/de3smbsg0kf2df4t6cmkijtadk/35662186746.pdfIn PDF document text
    • https://taptigrihnirman.com/singhania/downloads/file/15180009967.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ba186046975---86695176288.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/9025bc5b4bd16fbdcfff1dfbdd72cb62/tizexugomotirekaki.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/21832794637.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/d82397ef81a69dce87d814f81bd77cfc/kanutelalewagiw.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/66148619864.pdfIn PDF document text
    • http://songhandiban.com/uploadfile/file/2021072415172173499.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16095c035cebe0---nasujazesudub.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/suwapuwomupid.pdfIn PDF document text
    • https://mimpiindah88.com/contents//files/69418019332.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c29f844e91b---lubopivefabub.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/jarizafatorabotawa.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210530165300.pdfIn PDF document text
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/khpq02rgf28s7jpi2d6834j7kd/fuwudisapurebuzoga.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/4n9lqaf1du2brqf088jlatnr78/takexajidozugabune.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/rosowefudetekuputom.pdfIn PDF document text
    • http://sbs-group.co/userfiles/files/madij.pdfIn PDF document text
    • http://dagmar-e.de/userfiles/file/97963087467.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_off0000d1b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e9cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9CB 17844 bytes
SHA-256: 80e09c7294cb7036905985e5273386fc8fabd3f7bc40fc297f7a8397c6945226
font_02_sfnt_off000117ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117AE 10868 bytes
SHA-256: 2cf9050643afe26ee222136e2ea79b8258beb323275108cebc8bbeba65cbe6c3