Malicious PDF — malware analysis report

Static analysis result for SHA-256 31551afdba7ab6dd…

MALICIOUS

PDF

69.9 KB Created: 2021-09-26 22:25:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6ff85ef4a8206e864485b7ea00309ede SHA-1: 3a370f3c50e5707c46a832a7d737e8af0bb5c944 SHA-256: 31551afdba7ab6dd1e6115742faa02ac2ca010f8164448aff96d10702f661cbe
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or redirecting users to malicious content. The presence of external URIs and link farms suggests an attempt to lure users to external sites, potentially for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://bfull.ru/uploads/files/40852865186.pdf In PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16141639d426e3---45189588214.pdfIn PDF document text
    • https://spheresignal.com/app/webroot/userfiles/files/79354387168.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/nawofelutabojukewo.pdfIn PDF document text
    • https://tradingphrases.net/userfiles/files/53419551550.pdfIn PDF document text
    • https://honghow.com/ckfinder/userfiles/files/zekefevadeko.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613af73017227---wapezu.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/niniligemugofoziwoda.pdfIn PDF document text
    • http://newtarrytowndeli.com/uploads/files/44221431085.pdfIn PDF document text
    • http://exclusivelimoservice.com/ckfinder/userfiles/files/14657819344.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/13582715686.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/50711540052.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/12213286030.pdfIn PDF document text
    • https://2winit.com/Files/files/13629726602.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142006a06f24---xudakazonubof.pdfIn PDF document text
    • http://safetruck.gr/images/file/35839348086.pdfIn PDF document text
    • https://dailyiat.com/html_upload/file/84681896899.pdfIn PDF document text
    • http://posaonakosovu.com/ckfinder/userfiles/files/feveroligekomano.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210912_DBA1D561569E48D5.pdfIn PDF document text
    • http://simp-q.ru/userfiles/file/tisividanolem.pdfIn PDF document text
    • https://cheeselicious.net/UserFiles/file/10393863328.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161493bffaaa64---banunexuwove.pdfIn PDF document text
    • http://papinchess.ru/userfiles/file/69224697034.pdfIn PDF document text
    • http://www.tivafa.hu/upload/file/suwebozijurirudib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=watch+basketball+onlinePDF 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://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_off0000b2b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2B0 10452 bytes
SHA-256: 4c1ca447844f52ba702d47b1477043e2888d12e954fd5c2262577991833605c1
font_01_sfnt_off0000ca69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e27b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE27B 15744 bytes
SHA-256: 2f547866f402cf3c6547a35f473756677b75ef3d7902619e46e98520c0c996b3