Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ba2bbce0ccc34a…

MALICIOUS

PDF

79.3 KB Created: 2021-09-04 03:33:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 38b5d9c49cad43a337c8b216b7928ed0 SHA-1: 0170267ba95cac6d342462f8b85a1872f4ecc6a2 SHA-256: 81ba2bbce0ccc34ae72fcb100378612ceae6e4c4b0f3b6e88c2bba22255b4030
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 as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, directing users to numerous external URLs hosted on potentially compromised or disposable domains. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a tactic to leverage search engine results or compromised websites for malicious distribution. While no scripts were explicitly extracted, the nature of the link farm suggests it is designed to lead users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://catamma.ru/uplcv?utm_term=2005+toyota+4runner+sport+owners+manual PDF link annotation
    • http://setadijital.com/img/userfiles/files/84474967056.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ccab4e8c9---59854763833.pdfIn PDF document text
    • http://www.hz-kontejnery.cz/ckfinder/userfiles/files/9658343282.pdfIn PDF document text
    • http://www.naraihillgolf.com/admin/userfiles/file/70547900376.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/futomaru.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b136b6099b6---94755520606.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/zuxavezenovu.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/fed81aedee0bcd33fe801750a884db77/57014246787.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/48743798731.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/81592143346.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/zuwagojudebapunukusav.pdfIn PDF document text
    • https://nbtele.com/en/cache/fck_files/file/zipavegakipabutek.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/91928891412.pdfIn PDF document text
    • http://timandlor.com/userfiles/file/74585193525.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/50e096b2b6295e2106cedd2b54066d3b/58067154902.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd7e3813bf---betomavatinemebujizowuk.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/9872985578.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/likomibogipo.pdfIn PDF document text
    • https://proxus.nl/file/nikafipegu.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/72944993610.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/34285863678.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/0e3f92aa4fe5e22b1b88b999db7bf68c/42336003751.pdfIn PDF document text
    • http://xn--oy2b9bv81anouola.com/upload/file/202108100934047585.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/jikipitikopoxofujewixow.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0D 16640 bytes
SHA-256: ab09e3308f55035d9e0d09b12738f340f3effe2d023e8497e0e7654bc704f286
font_02_sfnt_off0001157e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1157E 10976 bytes
SHA-256: 45e11a818c01abd8eea1c1135a78caa027c087fe7deb8a8c82cda47c249fc031

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