Malicious PDF — malware analysis report

Static analysis result for SHA-256 da9bc683e35695c7…

MALICIOUS

PDF

71.2 KB Created: 2021-09-27 04:55:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 087a84a6ca9b3539f7f282287422e472 SHA-1: 22557924dd921036983cfd4ff5f3a194b8e4776e SHA-256: da9bc683e35695c7edeb5af01995644100fd70a2de64af3487819cf93bdb2d9e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to external sites. The document body is heavily obfuscated and unreadable, providing no further context.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://aqua2go.pl/galeria/file/58450245597.pdf In PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b91850aaa9---nowagudapogirenokafen.pdfIn PDF document text
    • http://otohyundaidanang.com/uploads/image/files/kukerineji.pdfIn PDF document text
    • http://dinhviht.com/images/newtech/files/85552485545.pdfIn PDF document text
    • https://karlholmbygg.se/UserFiles/files/72667212427.pdfIn PDF document text
    • https://shriramsteels.in/public/ckfinder/userfiles/files/80981082497.pdfIn PDF document text
    • http://insei.eu/userfiles/files/fewomuvutakepatugoba.pdfIn PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/mafawokafelijirivilero.pdfIn PDF document text
    • https://portecitadelle.portecitadelle.ca/ckfinder/userfiles/files/29082435790.pdfIn PDF document text
    • http://videlec.be/ressource/file/jekipuso.pdfIn PDF document text
    • http://33podarka.ru/pictures/files/monax.pdfIn PDF document text
    • http://megaprestige.ru/uploads/files/gipofed.pdfIn PDF document text
    • http://youngdongtec.com/userfiles/file/52734916797.pdfIn PDF document text
    • https://zoomkish.com/basefile/zoomkishcom/files/wapokotuvabiwesanimuba.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a70bdb12b---vebol.pdfIn PDF document text
    • http://tochuchoinghi.org/files/97372514993.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/fitevu.pdfIn PDF document text
    • http://magicfood-cn.com/files/20210918200339.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee1003c0bf---surosimegaki.pdfIn PDF document text
    • http://www.deewanalarab.com/up_imgs/noguxinunasunopipi.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library/File/kekafejuxokakujiwarukin.pdfIn PDF document text
    • http://kingsap.com/file_media/file_image/file/witakabakomiwibixan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=php+mail+content+type+htmlPDF 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_off0000b2e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000caf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAF8 17328 bytes
SHA-256: 4d7e53c5bc9f749bbdc844eb52e0e361dbf16db06e06f8cd7a61072df0c4f054
font_02_sfnt_off0000f7b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B6 10484 bytes
SHA-256: 049b845b928d640a0c69af6636574fb1a7704e767f024276d2c9cd9b478c3ac5