Malicious PDF — malware analysis report

Static analysis result for SHA-256 231b85eb0ad0f799…

MALICIOUS

PDF

83.0 KB Created: 2021-09-17 23:45:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7d13f00222a581f0a3adcae471064785 SHA-1: 0006d133d768d2017b4cc80eccb3a29f58fc57ed SHA-256: 231b85eb0ad0f799cae03a22be9068aca6732c4d84fc47c56d1720e9f1d61e35
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external URLs, many of which are hosted on disposable domains. The presence of embedded URLs and the overall structure suggest an attempt to redirect users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 https://queure.ru/uplcv?utm_term=astro+android+software PDF link annotation
    • http://space-edge.com/upload/files/6146997436.pdfIn PDF document text
    • http://inphilong.com/upload/files/niwujuwibawumumu.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/67801093264.pdfIn PDF document text
    • http://www.boldino-hotel.com/ckfinder/userfiles/files/83575268275.pdfIn PDF document text
    • https://nilsahost.com/calisma2/files/uploads/takoz.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/fafadapokekuvo.pdfIn PDF document text
    • http://bamor.org/userfiles/file/vorawivis.pdfIn PDF document text
    • https://diphong.com/uploads/xeduxilimabotobokesi.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210907_001751_137.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/sunulinizusine.pdfIn PDF document text
    • http://wawa757.com/uploads/files/wazawuxepevinowozunifiz.pdfIn PDF document text
    • http://tyros-club.de/userfiles/file/sidegitepe.pdfIn PDF document text
    • http://dfanchem.com/upload/files/gokunowumunusefogutik.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109161043234138.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/82873738318.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161345d7262492---pavukufakoloxirisevuxoz.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/tovoramelimijuso.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/pisapugabakefev.pdfIn PDF document text
    • http://wittymall.com/multimedia/userfiles/file/6525898270.pdfIn PDF document text
    • https://myclubowners.travelenvogue.com/userfiles/files/98807352230.pdfIn PDF document text
    • http://pololanna.com/user_img/files/manefudedetejinam.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d45aaf1e4d---3544465820.pdfIn PDF document text
    • http://01host.ru/userfiles/files/5489563094.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/72671404444.pdfIn PDF document text
    • https://jpt.mysmartedu.com/uploadimages/files/lisikosoduzezofuludo.pdfIn PDF document text
    • http://youil.org/userData/board/file/rivinakizutexukiwifujiw.pdfIn 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://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_off0000df39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF39 10368 bytes
SHA-256: a902f18cf5be0cfe7576d416dcf99a5be4cb18b741c2deb8a358172b2cea4e45
font_01_sfnt_off0000f6e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E3 18056 bytes
SHA-256: 8293f2478a9956e9653a9e4e9e8ccad3f852a06a905dc9d60880d9d72489adb5
font_02_sfnt_off000125e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1