Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81d4bbac1396487…

MALICIOUS

PDF

63.0 KB Created: 2021-06-20 10:59:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 7e18a26f51c3db6b5252f1b7e01e2c11 SHA-1: 95c6a71e4405550d836e97bb23baa88f44239670 SHA-256: f81d4bbac1396487a2204883785ce09321ab1ab51518df6e7b44ae8e685d33aa
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/7d6f6d2dab40a27ea26dfe1daf957388/87463556991.pdf In PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16075b1b01386c---49474066748.pdfIn PDF document text
    • https://cald-lighting.com/wp-content/plugins/super-forms/uploads/php/files/c459d106951b5c9607d6a279adeb3a8c/jizit.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/88216833641.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bf9873cbf6---tipofi.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/44071e5235507be0c387665ae5f2d971/bosasomada.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0e22a6853e---9895581276.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bd1115875b---jivikipuzobuseni.pdfIn PDF document text
    • https://arerp.kr/data/file/%5C/15459546414.pdfIn PDF document text
    • https://landi-bg.com/images/file/kulixorosovirijokisevi.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160911f4135930---87783481837.pdfIn PDF document text
    • http://wallsfamily1912.com/clients/876683/File/4886442080.pdfIn PDF document text
    • https://ancoraeducacion.com/images/61802819845.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/914f55b288b1e50b6a7dbbe4d5375a7a/3090903680.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160cbb42edd5c2---92193851176.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/461l8pvcvakpjduuk724ms15ko/87284287064.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/0a187ee474dee22d4f5c97597450c72f/95480165083.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160910a84befb0---93312179245.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=mr+bean+full+episodes+free+download+mp4PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b761.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB761 5512 bytes
SHA-256: 46c9cb04179123bf4dd97644dbc8c69e18ce870b883f9b7b6f6ea9952195ef33
font_01_sfnt_off0000ca25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA25 10652 bytes
SHA-256: 2705ad69d20e11f63bbe6e038ba7a5a54a3ed914b4c0b67d80541110fc8dd167