Malicious PDF — malware analysis report

Static analysis result for SHA-256 d2b423ee474cd302…

MALICIOUS

PDF

82.8 KB Created: 2021-08-02 04:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cb4a662edaafccd1d8df50d28d268052 SHA-1: 903572cb94ef42c144f000256ea0fbeeacd3dcf6 SHA-256: d2b423ee474cd302793f824e98f6075c519efbdc1ee841995eba77861c49cea7
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to various domains, some of which are associated with compromised CMS uploads or disposable hosting. The primary purpose appears to be directing users to external sites, potentially for phishing or SEO spam, rather than executing embedded code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://krisoc.ru/uplcv?utm_term=lesson+5+using+pronoun-antecedent+agreement PDF link annotation
    • http://crm333.com/documentos/file/2519127349.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/44220119229.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/5be820c5a5c38658a6540c3d15b25f6c/tomeburupaxalalejamezopo.pdfIn PDF document text
    • http://appinaris.net/ckfinder/userfiles/publics/files/lovugi.pdfIn PDF document text
    • https://baohohoanglong.com/userfiles/file/13460511294.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/59133aead0c59d95dcececcfd3399b16/xuwilaxopefasinizifub.pdfIn PDF document text
    • https://www.dgaspcsm.ro/ckfinder/userfiles/files/zoxisudexunomokerizuzek.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16077f09ebb3d3---solovodisowanukazanubexux.pdfIn PDF document text
    • http://wagnerpc.com/userfiles/files/kafojudedidubogobusevujam.pdfIn PDF document text
    • https://club-sports.net/uploads/products/files/bupal.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f33a9a0a9eb---vukafelamesubafejolas.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/dc3893ed8eae3a719aa1396bf4912320/xopenanilifiwogeve.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/68686794085.pdfIn PDF document text
    • https://blugarden.eu/file/71822091269.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/7173745953.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160760f1be27a6---84193164419.pdfIn PDF document text
    • https://thietbiotoviet.com/Images_upload/files/7471026318.pdfIn PDF document text
    • https://polnische-zaune.de/userfiles/file/50379362747.pdfIn PDF document text
    • http://abc-tel.ru/data/File/93706121513.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba32e899ee3---tixebi.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/540e3bdfe201255293b982b0504818fb/zexuxewawubutedixabig.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16100eb20d45fb---23861691580.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/mulebekapogowogupud.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_off0000ddcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDCB 11036 bytes
SHA-256: 95116426b68127b85178576b3dc8503c3ae66e7954bc55da8986166c70fa3519
font_01_sfnt_off0000f765.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF765 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F77 16828 bytes
SHA-256: a8b55800141511baa6dba7d954c56447c4a7f726834e8d9b103c15dc78fb3078