Malicious PDF — malware analysis report

Static analysis result for SHA-256 5811fb3f5a2914e2…

MALICIOUS

PDF

82.8 KB Created: 2021-09-22 21:52:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9c02b366166ed44068989661ebf6b9aa SHA-1: 7ad0fe088e07b7d5cc1677f70052cc99812a574e SHA-256: 5811fb3f5a2914e293ad3c3b985909ae1b150df84a5bedf0df50b7bbcf8d8d20
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a malicious tactic. While no scripts were directly extracted, the nature of the embedded links and the ML classifier's high confidence score point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.majbrno.cz/uploads/files/mimudojuzesuxamaborazopaf.pdf In PDF document text
    • http://soles2walk.cz/data/file/89373796899.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/joxezopalovuwimizejulem.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/76553012562.pdfIn PDF document text
    • https://graveyards-fuj.ae/userfiles/files/39064358854.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/sejofafasegojukobuwez.pdfIn PDF document text
    • https://nezamirekhaseafoods.com/userfiles/file/79503763135.pdfIn PDF document text
    • http://shesob.com/file/files/bojilaxufijo.pdfIn PDF document text
    • http://bradhelferlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xuvigedixasapuzijojilebiv.pdfIn PDF document text
    • http://clevio.biz/fckUpload/file/keneneg.pdfIn PDF document text
    • http://damosushipleasanthill.com/uploads/files/pobofewugerifugogod.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/bikifuv.pdfIn PDF document text
    • http://chieusangducphat.com/uploads/userfiles/file/jiziwugepeteguredezuzi.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/lakegikidiraxita.pdfIn PDF document text
    • http://jongauger.com/userfiles/file/nidafotesukitodizakajari.pdfIn PDF document text
    • https://yuvasarkar.org/userfiles/file/7817673785.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/80368990254.pdfIn PDF document text
    • http://sattosushi.com/uploads/files/74766398774.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/xawumaxinezozumokipaveso.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161326dfa6b0aa---67079400059.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/80404557918.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/23799283695.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/tuxawaloxuboxibelale.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=recycle+bin+in+redmi+note+9+proPDF 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_off0000db34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB34 18980 bytes
SHA-256: ab468cafc8acaed6698a5acf3f33b5ef744f7ce96940c781811d544cd5dddecf
font_01_sfnt_off00010cb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CB8 10812 bytes
SHA-256: c116f87817c1718b7e7982588663fce18e9bc9d668006c69e1e11764b8869992
font_02_sfnt_off0001256e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1256E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1