Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca0dea94751bfbb4…

MALICIOUS

PDF

77.4 KB Created: 2021-06-14 19:55:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 94387c1ff060534aba6b7358b71738be SHA-1: 25882e1273d0fa26e1853b92ac23548364aced5a SHA-256: ca0dea94751bfbb479e848a1633bac3d37d28cd52530ace43e64bf8995936b29
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by 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. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://synerhu.ru/uplcv?utm_term=song+let%2527s+groove+tonight PDF link annotation
    • https://aimara-bg.com/userfiles/file/23040794163.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160ab33fee7520---34550827669.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a5de080d53b---5710168214.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160aad2377b781---98199555156.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b974b786ad1---vexuvorezopodutoxomupure.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/78962522128.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/07d68383ae090e7cd31c4a33d0f8c2f4/7653440103.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abfefd8f795---64790270158.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/6cb52773ff5bcfc4c579d259bb02b45d/63350268965.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/bec46167747f8647f6397db0e3d5f194/61290367109.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160aced316dea4---fubef.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbab7a9e92---28663992193.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c0b7c8ca5c9---zanadatinadimewupuragi.pdfIn PDF document text
    • https://cabsfromheathrow.com/userfiles/file/pamegexowarenijetazev.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/78680770924.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e048.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE048 4932 bytes
SHA-256: d5c9df6977a2143aeb5a263807745799e9ec8f4d994bc3061588849a738ea95f
font_01_sfnt_off0000f116.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF116 2128 bytes
SHA-256: 0e0259ac06b5e63c9fbbe0b63de04b6375a8b8a1b56afe9f0e4286666c95e82a
font_02_sfnt_off0000fae5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE5 14220 bytes
SHA-256: 3f4305e62d3998f01be16eb31fafc80ab969dadf3c31d7a098e7b22575d01dae