Malicious PDF — malware analysis report

Static analysis result for SHA-256 18c9fa8f292a38b3…

MALICIOUS

PDF

79.0 KB Created: 2021-06-03 13:18:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 18f1fbe107a7dcbd6ac1ea204ad0b872 SHA-1: 0ed58831d42dbf237be8f4b22cba3355c9487400 SHA-256: 18c9fa8f292a38b3bedda93ac27c05b69be871abe105b9be3854ef2440804018
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, pointing to numerous URLs hosted on compromised CMS uploads, suggesting it's designed to redirect users to malicious sites. The presence of multiple distinct hosts and the use of UTM parameters in some URLs further support its role in a phishing or malware distribution campaign.

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 http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c79d206215---21352158990.pdf In PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607521aa59a8c---wajerimolavurog.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/2d09e61e8c356546fbdbbf0070ff0ed8/28582389807.pdfIn PDF document text
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609420519bae1---tageza.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b161e86e9d4---wezusenexu.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/3gqf5etn2gsp081r4gemfq08c1/29686131909.pdfIn PDF document text
    • http://innotec-industrie.be/userfiles/file/refafurikafuzunare.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/4bdc051da332b85f096d99186c46a78e/63069870803.pdfIn PDF document text
    • https://medprobr.com.br/wp-content/plugins/super-forms/uploads/php/files/35a609a7cbdc07b2e69588c1ae5c48f8/juxuf.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160847cacebd60---64912339524.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a3756447a86---befuw.pdfIn PDF document text
    • https://noddy.nu/images/file/fotigumafu.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/nojaz.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/6nhsedloj850lbda59fc0es575/16603050610.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160912d440bf08---rubelozofiluti.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/74917673642.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=verbal+irony+in+the+machine+that+won+the+warPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF755 5160 bytes
SHA-256: 59e54e2c9d58b9b76a3f31df9921260fa6acd03a6efa7c1933dabd835f7bce49
font_01_sfnt_off000108d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D0 11276 bytes
SHA-256: 5a1159c489b31f8c9bd6159d2120ba0bd61029b227151950c8d3e78f89612f24