Malicious PDF — malware analysis report

Static analysis result for SHA-256 91518d841440f427…

MALICIOUS

PDF

98.8 KB Created: 2021-07-13 22:15:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a235d82527c9e3a5e3b0f6fca5adbdf7 SHA-1: ae8e86ebb194ae0d4b6b5863a71fa19a627b6354 SHA-256: 91518d841440f42723ce87d335a48309c09a66b04f9862c87d4e5ab0ee26ac74
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains numerous external links, many of which point to compromised WordPress sites or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the presence of external links suggests the document is designed to redirect users to malicious sites, potentially for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://coretry.ru/uplcv?utm_term=the+two+pyrimidines+in+dna+are
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/4e912922c4a40a7c56f9855dd87d0dbe/sadasivumawe.pdf
    • http://agcslohian.com/userfiles/file/gosexunekuvumosezupe.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/1a731620a642d42dbc6c224cdea8557e/43768637238.pdf
    • http://miryangpension.com/FileData/ckfinder/files/20210705_A2FA6170C0143359.pdf
    • https://go2germany.ru/files/file/20660180826.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/5j4v9gt42rk319pafl6e2gblqa/tetifusojav.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160734ea7da49e---8238244283.pdf
    • http://timelessmebel.ru/wp-content/plugins/super-forms/uploads/php/files/dacd93445ec62b8764ce5288f7e06e68/ruvipelu.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7cff59200d---vutizatizojazibulukemif.pdf
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160818e1db2fa8---8137048959.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/60039947204.pdf
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16080583a8a43b---56024123200.pdf
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/749a23a60b19d7e3edac9afe24365323/1296926863.pdf
    • https://cafesca.mx/ckfinder/userfiles/files/23149728261.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/9pg3qbci33beb1tp38sv0kjdn2/82182262943.pdf
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/16088e40a27108---suralinubajisip.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1b5821fbf4b443330e509fd4df57ff93/podibikefekit.pdf
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c306bd41c97---81345704563.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011bcd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BCD 16792 bytes
font_01_sfnt_off000133e4.bin
6c410183b655f2ebe785aa7efff68468b9ec1e23143c0d8b54611ead6c2108b7
pdf-font-stream PDF embedded font (sfnt) at offset 0x133E4 10772 bytes
font_02_sfnt_off00014c96.bin
38a3e0025fb25782e4d03f83f6cf6d4b1696a1ac241def7057b32dc72b189eba
pdf-font-stream PDF embedded font (sfnt) at offset 0x14C96 18744 bytes