Malicious PDF — malware analysis report

Static analysis result for SHA-256 af4a205a4f4ffc9d…

MALICIOUS

PDF

87.3 KB Created: 2021-09-11 08:50:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ec96114c6ee85644ab1297d2d6b3e5e6 SHA-1: 6ca2f5bad674a210a860f713b264b4af6b907cae SHA-256: af4a205a4f4ffc9d0b237212a656083003a382ac08f3ae93bacc984b9e9b1122
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest a phishing or trojan payload. The use of wkhtmltopdf suggests the PDF may have been generated from web content, potentially to disguise its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://fishuntpesca.it/file/wowusa.pdf In PDF document text
    • http://aitrans.org/UploadFile/file/F1202109110944553700.pdfIn PDF document text
    • https://adikmanis.com/contents/files/22295642838.pdfIn PDF document text
    • https://nisahanpin.com/calisma2/files/uploads/8366538662.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/28481798400.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/19513688731.pdfIn PDF document text
    • http://www.jasolasia.com/image/upload/File/7047859663.pdfIn PDF document text
    • https://branchennachweis.eu/userfiles/file/konosokepalutunebuzejuxur.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/678faa8c56077beef1a7764c276bc685/kelewafajobero.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/67267028945.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/lopelivoka.pdfIn PDF document text
    • https://fainitelecommunication.com/public/editorfiles/file/39349819795.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/28076901268.pdfIn PDF document text
    • https://h16hr15k-h19hr37urn.com/contents/files/53035176187.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132a85c574e9---87689990156.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/bomolut.pdfIn PDF document text
    • http://dsagco.com/Upload/file/46557034944.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/1gpo06eel2bso9iq5evre29qt6/rinugexejimatufus.pdfIn PDF document text
    • http://piri-piri.pl/ckfinder/userfiles/files/80099052727.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/10683288801.pdfIn PDF document text
    • http://farmina.ru/uploads/files/wizuzidonasogumojekule.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16133308a444c2---95841065450.pdfIn PDF document text
    • http://patanjali.zohukum.com/ckfinder/userfiles/files/49083359751.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=android+save+game+dataPDF 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_off0000f09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09A 18296 bytes
SHA-256: a563182b91172c4f70c317d2e42586eb7fbae99e5141ae1143c9d3da99225a33
font_01_sfnt_off0001203e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1203E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013855.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13855 10592 bytes
SHA-256: b5ccbf5af42dfb0e16401d730b52481294923b48e29484e10e0a1dade13c45b7