Malicious PDF — malware analysis report

Static analysis result for SHA-256 ace551d7d8786834…

MALICIOUS

PDF

72.1 KB Created: 2021-09-25 22:55:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e356f32572337f740c2993ad9e3f6260 SHA-1: 7cd24ff1b2638acc80d8076d9feee90f9e1058a0 SHA-256: ace551d7d87868348ee7a074557f1b2e280164a74194a9e40944952697f18c2d
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. Several extracted URLs point to unknown or potentially compromised domains, suggesting a phishing or malicious content distribution scheme. The PDF's structure and the nature of the URLs indicate an attempt to lure users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://wisestudentz.com/userfiles/file/kipojuwadunasuwixa.pdf In PDF document text
    • http://kdekdyjak.cz/data/fanasabatomuzusenit.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/vuguxofeb.pdfIn PDF document text
    • https://taperagi.com/contents/files/23649726396.pdfIn PDF document text
    • http://knauto.com/upload/file///9753269584.pdfIn PDF document text
    • http://pomodorolennep.de/gfx/userfiles/files/jolifukalage.pdfIn PDF document text
    • http://nakloboucku.cz/uploaded/file/jujerojoxawuv.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/rafofumi.pdfIn PDF document text
    • https://netcsemege.hu/ckfinder/userfiles/files/jijovufukevekukenediwabo.pdfIn PDF document text
    • https://sogelec-eng.com/files/ckfinder/files/tagaxudofimazoveruvimi.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/68034081885.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/xefinejujamizeturepirud.pdfIn PDF document text
    • http://master-vin.ru/files/file/garugenojafabipurilurez.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/qaq5utf8t7vm1s0c8dho3vaij5/14740395059.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613197b889fa3---sufuwagevutiron.pdfIn PDF document text
    • http://cityfate.com/files/files/31432616593.pdfIn PDF document text
    • http://hyswimpool.com/userfiles/puroxuwu.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/c316d13d28ac1603d5d7f1da0ead24fb/piveguv.pdfIn PDF document text
    • http://xn----1-6cdapb2bdyqawnpcindqfc.xn--p1ai/media/file/voterizamuzibedol.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/busimikipunoveluxigoga.pdfIn PDF document text
    • http://preiss.at/upload_files/files/78627272459.pdfIn PDF document text
    • http://elitaliaweb.it/upload/file/63857815864.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/zosebuvulejimonepanu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=conditional+sentences+exercises+multiple+choice+pdfPDF 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_off0000b4e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4E2 16960 bytes
SHA-256: d61c4335856043bc8e44915fbe68c1ddecfd3b06cc146447cac4d80f787cec0b
font_01_sfnt_off0000e042.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE042 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f859.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF859 11120 bytes
SHA-256: 2d03e6896ec3e5405ac0e9301d86d95445b5cf27b7915c37e5fca36044c2bf4d