Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf760b519edca7df…

MALICIOUS

PDF

77.9 KB Created: 2021-06-18 13:47:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 9ba15abdbb2e1c8ec03ba116a7eaa18a SHA-1: 7c9e153a9fa5d4ce03d635d97109ad8d6c24008e SHA-256: cf760b519edca7dfe5fc77194ada0277a6cc29bd0f08bc92a7f77b4e0b5ada1c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm with numerous URLs pointing to external sites, many of which appear to be compromised WordPress installations. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://queure.ru/uplcv?utm_term=desafios+para+el+desarrollo+y+bienestar+colectivo PDF link annotation
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/8de2239b8f100aaf483832417c0bf812/jalupepupujoputobo.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/94652826293.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/17272991663.pdfIn PDF document text
    • https://ratsimae.eemedia/contents/file/2767559756.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4f37d2836---jogimamen.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf7f01d8eb---sudujafani.pdfIn PDF document text
    • https://imad0c0.com/js/ckfinder/userfiles/files/42186676580.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/degabemaxuxapexujolofera.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/351455977246f25ef17c1b774383ea93/vomowoziz.pdfIn PDF document text
    • https://rintrans.com/files/dutoresitaz.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/09cb4552478da2966b787a4b3e449191/xitokosisovujibutonowo.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/5nlj69arevtfdh6b3qle9o49n0/mavome.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160acef9ddb262---3396666203.pdfIn PDF document text
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/ea2765ca52e126978f5fad0895af7568/jadafudelu.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607220b7efda2---vobewelotax.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file/%5C/74909803897.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_off0000ecf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF2 5448 bytes
SHA-256: 441aa473c115812406ae78536bf2b57ac1c80d25ca6889cf43e6eedfe0b172d1
font_01_sfnt_off0000ff9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9C 13032 bytes
SHA-256: 8f9a56c823f34e7296e87fc03bcc35de5696d79714f20e97aac0912fa087986b