Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b631f0662a702e2…

MALICIOUS

PDF

66.8 KB Created: 2021-06-18 22:57:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 8a0b1735414f73f3e6117e49ca35de13 SHA-1: 75684be92d8359124f7decb737449061cc94b320 SHA-256: 0b631f0662a702e22c2b5e93569aea63e066a10348a8bcdf1447b5d2df34ba72
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file contains a large number of embedded URLs, many pointing to compromised WordPress sites or disposable domains, suggesting it functions as a link farm for phishing or malware distribution. The presence of these links and the overall structure indicate an attempt to lure users to malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://krisoc.ru/uplcv?utm_term=stardew+valley+blue+chicken PDF link annotation
    • http://syuncyoku.jp/upload/file/40577541898.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7ab50920f---tovukewafedagar.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/cc28207407a2b087e88669c650e20b2b/61134762334.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/181916492541.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/mugufur.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/81103501313.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091f4997daa7---97941435882.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/barawapezalodo.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/b123d872e218b41f640743319b3e79de/fuvimovu.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/7a72ae30a5a45ca71e2c980755f2a6d1/lufonuvu.pdfIn PDF document text
    • http://wabasnb.com/files/fckeditor/file/71376999060bc481863331.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609609bb61013---89712275081.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e4178479f---79545704200.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/qoncvmb77vngqtmcovet11srg6/76287972122.pdfIn PDF document text
    • https://hoalavender.net/upload/files/71971798039.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088b4919e973---najabebalenuguf.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC47A 5408 bytes
SHA-256: 929b29b168ae8426a8fbc8dbd38baef6ec21edc2d93aeeb2cc54b152cddc4112
font_01_sfnt_off0000d6f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F4 11852 bytes
SHA-256: 74b7d1a34d885e6a300e4109cff820827a42169cf0c55a12e9026b2fb5f6d361