Malicious PDF — malware analysis report

Static analysis result for SHA-256 21375c0b0028101c…

MALICIOUS

PDF

69.1 KB Created: 2021-10-05 14:11:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4077c8719fbc972c7a1118a0d5876e94 SHA-1: 9e1130c32f0d50e6a7775e33f17f47c1aaee892b SHA-256: 21375c0b0028101c8a4f3d392af268c957d5b3bf6894622f19576fe70f075973
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a large number of embedded URLs, many of which point to disposable hosting and utilize UTM parameters, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a phishing lure, likely intended to lead users to download further malicious content or submit credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://catamma.ru/uplcv?utm_term=at+the+airport PDF link annotation
    • https://igk-lilienthal.de/downloads/wezufezifu.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/jatejutabilifisefapuvixi.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/tuwomogomurifuzawibetuj.pdfIn PDF document text
    • https://ww150003.linebot.net/upfile/files/20210909152754.pdfIn PDF document text
    • http://sutipatika.hu/userfiles/files/lezowoguvovirapusil.pdfIn PDF document text
    • https://pracowniatechart.pl/fckpliki/file/6109398395.pdfIn PDF document text
    • http://excellent-art.com/userfiles/82092017957.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/29429061424.pdfIn PDF document text
    • https://www.delaneyllc.com/ckfinder/userfiles/files/32437674212.pdfIn PDF document text
    • http://www.eurosecurimed.com/ckfinder/userfiles/files/72178384273.pdfIn PDF document text
    • http://ck-buhgalter.ru/userfiles/file/polejokajesutadopozu.pdfIn PDF document text
    • http://saveursetsavoirs.fr/image/file/dejevosovedukavu.pdfIn PDF document text
    • http://dkmmotor.com/files/userfiles/file/kopifadusewu.pdfIn PDF document text
    • https://promise-land.com/upload/file/14143184287.pdfIn PDF document text
    • http://kruengrangthai.com/files/files/18364917949.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/91393599770.pdfIn PDF document text
    • http://koreadramatour.com/FileData/ckfinder/files/20210920_0724525AEE10F64B.pdfIn PDF document text
    • http://harrodsrentacar.com/public_html/userfiles/file/bagokajida.pdfIn PDF document text
    • https://tbsva.org/Upload/files/20211005024654.pdfIn PDF document text
    • http://le-nora.com/userfiles/file/21764647612.pdfIn PDF document text
    • https://bahamianbrewery.com/ckfinder/userfiles/files/xubinexejumewudafegu.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/161516384de715---wuligefevopokegabu.pdfIn PDF document text
    • https://topconta.ro/userfiles/file/28437856429.pdfIn PDF document text
    • http://openendrep.com/userfiles/files/fanowiwetofuporipe.pdfIn PDF document text
    • https://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/29966813669.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_off0000b386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB386 14664 bytes
SHA-256: 6550794f7be9100a513beeae24340b58ae2bcac0bbab163049f6e9986c7f13ff
font_01_sfnt_off0000d857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD857 10012 bytes
SHA-256: 504251b24bc5b61620f2d31fd1f8e05c7c0067a308833ebe6e22cb5332de2715
font_02_sfnt_off0000eeb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1