Malicious PDF — malware analysis report

Static analysis result for SHA-256 255e46a055a9a592…

MALICIOUS

PDF

88.9 KB Created: 2021-06-25 15:50:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 0926d482ec1cbe856bdbc115f6c4ee64 SHA-1: 5b1d487db50f42b18522c48ddb6665405c336019 SHA-256: 255e46a055a9a592edfd3c753ddaaafd0a41bd13bd399facfa832ecd4b6a2de6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to lure users to external resources. While no scripts were explicitly extracted, the nature of the embedded URLs and the PDF structure strongly suggest a phishing or malware distribution vector, aligning with the Spearphishing Attachment technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d22f28a4b7---vogoborefezosivopuxexamut.pdf In PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-5-7/20210507023119705653.pdfIn PDF document text
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/4e7be87ee8c5be8e2dcc9fcfcc825b08/rapipib.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/vifarezexanofub.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a1472762d5e---98639448370.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cd1890082ea---831362012.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/juvukawunikuxeketudado.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a27f62de14a---kozopafijosamabowijulisu.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4831ef1a50---lasuvipaki.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/83202976398.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160808f2d336cb---37956945627.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/peko2i1qvuqk78mjudpkb7s2lj/16531375383.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/402697c5f4b8fbacfbe87f5442ea785e/38515432541.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16089873d1cdee---22420539438.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/mebebejasosem.pdfIn PDF document text
    • http://sparkpro.lv/content/file/2845700764.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=group+2+on+the+periodic+tablePDF 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_off0000f6b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B0 10844 bytes
SHA-256: bb28a4a7dac634a10b29576c6be3ce7303f2c2da5d1aecc8900e6f24bce56b5d
font_01_sfnt_off00010f74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12786 17500 bytes
SHA-256: a31a7a8949aef36a15012fb22213f11d8d8cf73fd069fae9203c3a1d9759673e