Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7311c93b3d2c0e9…

MALICIOUS

PDF

77.4 KB Created: 2021-09-16 05:31:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 19e85b0f7a9849019cffd75b6b44eb55 SHA-1: f064aa0518fa17b9513f121d93fdfcc0f4ce5a59 SHA-256: f7311c93b3d2c0e97c2fddcba4eaf7121a0be431a91014957d5919683a0c6e2f
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting it functions as a link farm to distribute further malicious content. The presence of these links and the overall structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b185e0361b---2873293452.pdf In PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/e9f224e6f6f7a2f2b29dde4df48fb4f8/vedusupabofezitox.pdfIn PDF document text
    • http://pandoraecza.com/genelresimler/file/vifenoditaminupitiw.pdfIn PDF document text
    • http://gabinetortodontyczny.eu/userfiles/file/21271077007.pdfIn PDF document text
    • http://expresskaliski.info/file/44143726388.pdfIn PDF document text
    • http://ugrctrani.it/userfiles/files/30791210211.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9766757ba---43980295232.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/sovolositup.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109020943148539.pdfIn PDF document text
    • http://ototavandosemesi.com/resimler/file/52313352806.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/17111604052.pdfIn PDF document text
    • http://zonweringbelgie.be/ckfinder/userfiles/files/5307280616.pdfIn PDF document text
    • http://balalajka.nu/media/40888423348.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612eba0e24e41---92018755599.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/93535331723.pdfIn PDF document text
    • http://fd-health.com/upload/ckeditor/files/64524614178.pdfIn PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/57979691127.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/wetugumorolitikifev.pdfIn PDF document text
    • http://e-district.org/userfiles/file/devuvetopanevafunawe.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/93604094.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5425ae5cf---50404808320.pdfIn PDF document text
    • https://siam-royal-view.ru/data/files/97466957800.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/2e2f6eccfbd041e61347bf330c25114b/59127870445.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=redmi+note+9+pro+camera+functionPDF 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_off0000c68b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC68B 18408 bytes
SHA-256: 55fb07976d6f71273526efcab7967fbb0748f1e6ffaae6f97071dde967c45042
font_01_sfnt_off0000f6ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CE 10880 bytes
SHA-256: e71b88490a8877e34fb9180b344d551da6bddb05e4a018b359f9a1254049ed44
font_02_sfnt_off00010ffc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1