Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b8771b8f4157d73…

MALICIOUS

PDF

72.7 KB Created: 2021-09-29 02:54:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d88d118c99eda1454e0fc390e144f627 SHA-1: 0f5b27be73044488fe67b64337a7e03f30824275 SHA-256: 4b8771b8f4157d73bc3691e8015e528ff082a286f28fbd1a309a3bee3b523eac
126 Risk Score

Malware Insights

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

The sample was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism to deliver malicious content. The PDF's structure and the presence of many external links indicate an attempt to direct the user to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vectorma.ru/uploads/assets/file/xokik.pdf In PDF document text
    • http://swatimishra.in/uploaded_files/userfiles/files/zazuridanixojakinagup.pdfIn PDF document text
    • https://motelandratecuci.ro/userfiles/file/9998783237.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/rekozuxelejogarukiduveton.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/9525211715.pdfIn PDF document text
    • http://www.solarwindependence.com/ckfinder/userfiles/files/98860566032.pdfIn PDF document text
    • https://by-express.com/upfiles/editor/files/14969904905.pdfIn PDF document text
    • https://smilaxlabs.com/userfiles/files/42884459657.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/sabosalinexujenobawapo.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131bb575fbb7---bidapiwirugaw.pdfIn PDF document text
    • http://jutaek.humenia.com/upload/userfiles/2021/09/files/210905040045.pdfIn PDF document text
    • http://cortocircuito.trialpanel.com/images/Upload/files/supasepezerelamev.pdfIn PDF document text
    • https://unitytradefze.com/ckfinder/userfiles/files/kugenorerurogepogam.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/55152987456.pdfIn PDF document text
    • http://tatvan.in/userfiles/file/77947886202.pdfIn PDF document text
    • http://penzion-pod-rozhlednou.cz/img/file/losidizagifabediwuvile.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/38522245508.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/ab1ce20259c3d695ee59c52869936256/zebofejakogoluwo.pdfIn PDF document text
    • http://classtool.info/upload/files/39535073102.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-26/20210926162823490931.pdfIn PDF document text
    • http://www.diplomat2014.ru/ckfinder/userfiles/files/71160219207.pdfIn PDF document text
    • http://akcihlar.cz/userfiles/file/41071918870.pdfIn PDF document text
    • http://interface-referencement.com/userfiles/file/11907893132.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=mi+a1+safe+mode+offPDF 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_off0000b46b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB46B 10212 bytes
SHA-256: 096d8490abd95d0e13cbf3d3197bbc299bad6e5d85b82f61140e7a821a547871
font_01_sfnt_off0000cb61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB61 19336 bytes
SHA-256: e0a9a56b3d2afcea40878d4c3f5c0da1a68bb73c881b0cadb454d0e9c482deef
font_02_sfnt_off0000fdd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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