Malicious PDF — malware analysis report

Static analysis result for SHA-256 8456ac746d6ad458…

MALICIOUS

PDF

82.4 KB Created: 2021-09-12 03:02:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: dd2d3a3115676d9d5890aa2759e14d26 SHA-1: 9d38d4c4b85e67bd76f0349d0814970c31c590bc SHA-256: 8456ac746d6ad45840761fa660c9bbed2c98b72fcbab0b70a2ed48e4424a3f02
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document contains a significant number of external URIs and link farm patterns, indicating a likely phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but likely serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://pistant.ru/uplcv?utm_term=mortal+kombat+apk+for+pc PDF link annotation
    • https://citronel.com/userfiles/files/jenituxafopujewumu.pdfIn PDF document text
    • http://digifast.cz/userfiles/18951566078.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/puwafowu.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210909_0F59B96EFFA087FD.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613915c03ad58---febajunop.pdfIn PDF document text
    • http://administratieindex.nl/images/uploads/retokuzuf.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f27712353---gijalifake.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa0858b577---47748468522.pdfIn PDF document text
    • http://drkoopman.nl/cmsimages/file/topudujes.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/4437924055.pdfIn PDF document text
    • http://bjavc.com/filespath/files/20210911212723.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/38752727302.pdfIn PDF document text
    • https://chorland-dining.com/webroot/editor-uploads/files/44549490726.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/rimozofe.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613394144ac99---zowajefifabifumo.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/37389869746.pdfIn PDF document text
    • https://apra.pl/files/file/69572022707.pdfIn PDF document text
    • http://www.enfersalus.com/ckfinder/userfiles/files/makoxikurureduz.pdfIn PDF document text
    • http://achwvs.love-mrt.com/upload/files/19116219794.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2c9144664---bigarofawakokasesiju.pdfIn PDF document text
    • https://soudurelausiere.ca/upload/editor/file/jumoforikara.pdfIn PDF document text
    • http://xn--c1aejbdnke.xn--p1ai/admin/ckfinder/userfiles/files/janokiwub.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_off0000dce9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE9 10372 bytes
SHA-256: 456d8d55126edc08ad5fc3622b8d34f73bf52120a925ad6e808d9b6674c50daf
font_01_sfnt_off0000f432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF432 18328 bytes
SHA-256: ae33bb501637b36101ad78411dae7215d3bb26381edee46c8f8840cfea294431
font_02_sfnt_off000123cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1