Malicious PDF — malware analysis report

Static analysis result for SHA-256 4681c8ebd6213d84…

MALICIOUS

PDF

82.0 KB Created: 2021-08-31 20:16:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 2d1a20a7f0f48ee43b054ed2b35f71a1 SHA-1: 3b62b748eeea5f9a613cee74edad9733c78f610b SHA-256: 4681c8ebd6213d840e532e93c15abc78c00daecc874d5e28d2b29f541ff56fac
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites. Heuristics indicate this is a link farm, likely used for SEO manipulation or to host phishing content. The ML classifier and ClamAV detection strongly suggest malicious intent, with the URLs serving as the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/inmjqehitnamcjd49ifoh7jntm/51459564456.pdf In PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca554c398d---zojeretajugoxaro.pdfIn PDF document text
    • http://rosesrealtyhomes.com/userfiles/files/56536028721.pdfIn PDF document text
    • https://krono-original.vn/Images_upload/files/jebunupu.pdfIn PDF document text
    • http://thaihotelsale.com/FileData/ckfinder/files/20210625_30F4381EF3437E2E.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/12989205362.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/12485165.pdfIn PDF document text
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/160720e5ede580---fotasaxif.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16100ebd43013d---59423460972.pdfIn PDF document text
    • http://zzweien.com/d/files/24949628065.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/xibinoxafejimalimapepubuz.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/56f0d103deac6d77added8e4eb755976/69292203796.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/gojikafo.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160888e6eb9f1a---53316039617.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/165644864790e157692a56e63ffa9106/14541427871.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dcdc39bcbdd---74983825405.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161130c9604fc1---31146653349.pdfIn PDF document text
    • http://kimdaiphatsteel.com/Images_upload/files/62004209046.pdfIn PDF document text
    • https://smartcrm.cloud/upload/files/8585333358.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/b62f61d653621c2bc2c24325788f2271/pejapa.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/859c483ee39f7bb39cd2337a5c76196d/xabon.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/97347743384.pdfIn PDF document text
    • https://suma.ca/upload/editor/file/wevumifuzasogofawe.pdfIn PDF document text
    • http://bagumul.com/file_upload/spaw_upload/file/20210516025644.pdfIn PDF document text
    • https://tedesco.pl/userfiles/file/sodizemolepegow.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/29946705439.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=proletarianization+refers+toPDF 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_off0000dbfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFC 17864 bytes
SHA-256: 6c479dc55b8790cb2d637d780debee8b08329f42fc073a4e1b44468542ec89aa
font_01_sfnt_off00010af1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012308.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12308 10268 bytes
SHA-256: 04f5fa093e37108c2948ade094085d83594678e33dadd952b67eb112801b3242