Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ac40c41ca5ad70e…

MALICIOUS

PDF

84.1 KB Created: 2021-08-17 10:52:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 41bec8aef9cd5adf1eb2d46300fc08cf SHA-1: bbe7faee497f142bbb7e6c5eb3232a19a784ee4f SHA-256: 6ac40c41ca5ad70ed5046fc435d28839beb96dd4d84e58b41203147018e65ffb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on compromised or disposable domains, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery, likely via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://ketchas.ru/uplcv?utm_term=o+que+%C3%A9+um+processo+endot%C3%A9rmico PDF link annotation
    • https://allcreaturesinc.com/files/files/64598992428.pdfIn PDF document text
    • http://tksvolga.ru/userfiles/file/89975160768.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/buxebasep.pdfIn PDF document text
    • http://vakoplus.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/85870994918.pdfIn PDF document text
    • http://chono.mn/uploads/userfiles/files/xadakijas.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096430e1fc73---96281109089.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/33272826393.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c3b0644dca2---rarogavel.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/6vtjjor8ttvl4ktufttv74f1n7/61020864923.pdfIn PDF document text
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/lupatirokupuposukogo.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16074a5f224400---sewef.pdfIn PDF document text
    • http://verdantnorwich.com/clients/3/30/306756bb587dffcd11ca74610d845a16/File/govaboxazib.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/gisavimobipekodenodoxeme.pdfIn PDF document text
    • https://mimpisiluman.com/contents//files/9007632429.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/nuduze.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/bebemexefujabatejotin.pdfIn PDF document text
    • http://championsview.net/userimages/pegixapevowugifew.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/fomudanosubifodiridivikak.pdfIn PDF document text
    • http://tinhdaurosa.com/Images_upload/files/42721501229.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/2756749591.pdfIn PDF document text
    • http://xsjprinter.com/d/files/97804587065.pdfIn PDF document text
    • http://linker-apps.com/files/85098701255.pdfIn PDF document text
    • http://newcastlehigh1967-50threunion.com/clients/43248/File/19000877481.pdfIn PDF document text
    • http://k1a.ru/images/files/file/10358986714.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/nemilir.pdfIn 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://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_off0000dd23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD23 20372 bytes
SHA-256: 6c3170ab6565c5786574795ffc7d7a77daba39d88ae4869f4e8493ec8cdbe551
font_01_sfnt_off00010f85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001279c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1279C 10892 bytes
SHA-256: 38d82c5c41b12b45ba0d063334ae481a937d5721d51e0b3bbb061415d2b3178e