Malicious PDF — malware analysis report

Static analysis result for SHA-256 a31869416c52607c…

MALICIOUS

PDF

72.7 KB Created: 2021-06-25 12:09:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 9c0db9d59393b9571e40d594b4e59cd9 SHA-1: c228de26398eaaf509217e48584a647d3cca3217 SHA-256: a31869416c52607c80aaf35dba444f712297f226de4100dce4027fcd40dd8991
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by multiple heuristics and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics strongly suggest this document is intended to redirect users to malicious sites, potentially for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://irlanc.ru/uplcv?utm_term=arun+sharma+quantitative+pdf PDF link annotation
    • http://anhuifan.com/upload_fck/file/2021-5-2/20210502210447869775.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9161a0f95---xovuvododobenerijolop.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/wavigowakulebob.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b6dbcd5b316---17843379707.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b17047ee552---meluz.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/n62i5di2v80c8rkaufo1523j90/8444870678.pdfIn PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/49524044731.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/metuvumus.pdfIn PDF document text
    • https://nestaerospace.com/uploads/file/11066061874.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/jetalumofe.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/f4a15inelvu6kf6hbuudncdlf1/10089241100.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/89g3i2u1vt6k8rgrupmskpdql7/sanejazetidofu.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/xudode.pdfIn PDF document text
    • https://equinox-e.com/upload/files/parutarapoge.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b7589f86d5d---tenona.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607f65cef28c6---42005355725.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/47d890585c7d7d1a65c40b4582315c09/nosuwolevuno.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_off0000b81e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB81E 10892 bytes
SHA-256: 7e7cedc65911e84946cfe93dc997c193735aa3f6a7f1bdfd0eb097732f28a06b
font_01_sfnt_off0000d0f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e905.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE905 16868 bytes
SHA-256: 9467c0f9f12e4f970c222061a1ed90f6bda6c51620aacbc361138cb09e82e48f