Malicious PDF — malware analysis report

Static analysis result for SHA-256 316b7319406d701f…

MALICIOUS

PDF

98.2 KB Created: 2021-10-12 12:31:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: db59f82e0de7de8b9078f147b8b4c9f5 SHA-1: 645c51d4f98116e122c6594c16f133337d28ca5c SHA-256: 316b7319406d701fb7ed81e8fa1a3bfe23d43a656bf61eb8ec3efd14b1007c4c
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The document body is unreadable, but the presence of numerous URLs and the nature of the heuristics strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://www.propper-droppers.nl/files/file/33936575055.pdf In PDF document text
    • https://bruceautoservice.com/files/file/65881601609.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615a3af7d4d68---bagorotopoxorenapolakabop.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/batekomototijadokudusujuz.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/22656286560.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/73389298774.pdfIn PDF document text
    • http://snabsz.ru/ckfinder/userfiles/files/54810499287.pdfIn PDF document text
    • https://sakura-bashi.com/uploads/files/202109300443543364.pdfIn PDF document text
    • http://jadever.vn/Images_upload/files/4204942448.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149e3143e4da---dulimuwunesudedeme.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/53031503573.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/juzime.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613c824b49929---wunajutuvakinolaxadorimu.pdfIn PDF document text
    • http://bergepkolcsonzo.hu/userfiles/file/manapogizogosuve.pdfIn PDF document text
    • https://baobiachau.com/luutru/files/wateratuxopizufogupedip.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/2812007146.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/65364186530.pdfIn PDF document text
    • https://petpetmates.com/files/editor/file/19687754184.pdfIn PDF document text
    • http://tzoetemondje.be/uploads/files/24280906459.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/95553877683.pdfIn PDF document text
    • http://szhlfz.net/upload/puxivafewatemawam.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149aadeced01---xupumigumidol.pdfIn PDF document text
    • https://klaipeda.cvzona.lt/resources/img/files/lomagijumodozuse.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/cmwvf4RlXg4/uplcv?utm_term=strong+electrolyte+examplesPDF 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://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_off0001139f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1139F 21000 bytes
SHA-256: 7035443d3a34a4a46d3d031c00d9dda5efd687aa1b8bf77637da530f7f90bf54
font_01_sfnt_off000149d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000161ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161EA 10916 bytes
SHA-256: c371fcadbc06557b800fd4f03c16086f5c59646df9c184a2bd17afe66cd8c08e