Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4c3a7597b8e7cf9…

MALICIOUS

PDF

70.3 KB Created: 2021-05-23 03:12:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: e84242b99e2c23fa8951485801fb5f78 SHA-1: 3eb2b3ae5516480f43440e8f1b6ccf14b0f4aa66 SHA-256: b4c3a7597b8e7cf907cb75e5a4ad9f4862b1c45312030aa938ef1638289da4ef
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 0.9997

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 http://birnagarcollege.in/userfiles/file/94921189887.pdf In PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/74a5c00d8e79ba07857068152244f8a2/15077941586.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607961760d113---wigijivovenojonituweradow.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/679ba05e58c935cf67bb3bdefd45dbe2/rurazutuwomuvefilegozopa.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/dipedubinulazafogigijiw.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4441313db---xilisotukafupubosi.pdfIn PDF document text
    • https://lastcallslc.com/wp-content/plugins/super-forms/uploads/php/files/5092ba8516fdd144fcce19bb207971cb/kaneb.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/d92c0468a4c9354702da8060ec9e302e/sulabipiliw.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609230bfe3039---42451311544.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/jfn1lrqibgbicfig1c5dg6smaj/77719433136.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/e52b3ec7ed016487f7ff5b155bf1fdcf/12722397697.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/5199de45b91dc321022c4b631312bef3/kujolipipenuposixuxi.pdfIn PDF document text
    • https://carpanea.it/wp-content/plugins/super-forms/uploads/php/files/754930069f388bd9e638841ce908dcb4/96140230406.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/46uh7i1l0fsdc81gjvrnpksnue/jubofonatuvaposisid.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/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=how+do+i+turn+on+microsoft+wireless+keyboardPDF 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_off0000d2c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2C5 5528 bytes
SHA-256: 062effa31af1ec771f246df9dd2effbb2cc42c379f263981e9cc5632ad4dea2c
font_01_sfnt_off0000e58b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE58B 12508 bytes
SHA-256: 9fedaac5159a283f796b15b6f7a1e329c4fac4b132328890ee75f10e7bd43941