Malicious PDF — malware analysis report

Static analysis result for SHA-256 851113e1f1e35b80…

MALICIOUS

PDF

82.0 KB Created: 2021-07-05 10:09:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 53b30465c8f69c0ed62dea41bd438ecc SHA-1: c501cf7e4cec2fae202770b17199a61d6b3896d4 SHA-256: 851113e1f1e35b80e81aa13685dcfda20de769a57d195f510384cac844945bf8
176 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 a phishing trojan. The file contains numerous links to compromised websites, many of which appear to be WordPress installations hosting malicious files. The primary attack pattern involves directing users to these compromised sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://crysiq.ru/uplcv?utm_term=there+are+4+consecutive+odd+numbers PDF link annotation
    • http://maihome.hu/admin1/file/fizabesodule.pdfIn PDF document text
    • http://cn-junsheng.com/upload/file///2021611102364816.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d0bfa772e---49268703941.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609be614b37e2---labunezafal.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/figilitobarubiwuxeva.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ae65a055432---vetonogaputajogurike.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/dorimilomisa.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160934c8235576---gekorozawalozoveraf.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/tuklojkutmlvjno0kphfgr8140/dekazosiroge.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/14911334414.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/84932973952.pdfIn PDF document text
    • https://tailormade-sales-marketing.com/userfiles/file/pokalanetetupijozuru.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/f1976bc787554e2b1c0dcf5606b15f18/koxixufidifaxi.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/160c6765cee267---vejofajepuvavenane.pdfPDF link annotation
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160903e62d681a---jeripi.pdfIn PDF document text
    • http://teifsepahan.com/files/file/50537491986.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/janarupewelejusus.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160920a4500ccc---7644853956.pdfIn PDF document text
    • http://anatolianlgs.com/userfiles/file/sewob.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/au0u3re607bgopeq580gulecjj/41882662163.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/95b81fcc7b60405ce4e4714cc0ffe594/pubilopel.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/wafosarosexurupuludate.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/28e1c6e05e4d3156f72ea9be17fbc246/20360942253.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/69070735681.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aec5890f9f---jiwegasotilonodek.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c5d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5D8 10936 bytes
SHA-256: 504fd58f8bffbc9a46ecd14117cce8f8c41d60caffa0f0bd642fc0f1c71b99c1
font_01_sfnt_off0000df1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f72e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72E 16396 bytes
SHA-256: 7ca50face42b81415bfef5f2263a25a1bf22ace044cd1930a40731e8e12860f3
font_03_sfnt_off00010db2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB2 16908 bytes
SHA-256: 8a84ef965b5c20730177efbc40eb3a56a99cbd3f6fe74d004527dc42c24bb683

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