Malicious PDF — malware analysis report

Static analysis result for SHA-256 e51323f705429fad…

MALICIOUS

PDF

87.8 KB Created: 2021-09-14 05:04:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: eea7a8f875efa1b030bd42df4df6b6a9 SHA-1: d8a0ff944f2b148c33ed607776e45161e0054f1b SHA-256: e51323f705429fada7d2bccc146255e0b535ca9ac08ba54e5449d81752f1f5a2
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to distribute malicious content or phish users. The primary attack vector is likely Spearphishing Attachment, leading to exploitation for client execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://mofrantech.com/userfiles/file/zajadokosora.pdf In PDF document text
    • http://gusanhightec.com/userData/board/file/5768786053.pdfIn PDF document text
    • https://flavio-tonon.it/public/file/85746478785.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/sapowogufagobulotomipoji.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613669d6d805f---42490939698.pdfIn PDF document text
    • http://aasghsflqsae.handylover.com/upload/files/kiwomomugijakenufub.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///rejenogituzakitofokugefaj.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/19830441906.pdfIn PDF document text
    • https://hotararicedo.ro/files/files/wasutimodekezedotani.pdfIn PDF document text
    • http://chromavials.com/d/files/27353273361.pdfIn PDF document text
    • http://dom-2000.ru/ckfinder/userfiles/files/fuvuzogilolutelamaso.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/2863261123.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/xikiwupuzev.pdfIn PDF document text
    • http://klpa.net/userData/board/file/mexir.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/wesafadir.pdfIn PDF document text
    • http://amicissiapiemonteisa.it/userfiles/files/57345219301.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/piramozizujovixilupux.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/samivokalisusotili.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/3985061543.pdfIn PDF document text
    • http://trunghungplastic.com/luutru/files/linifipokuku.pdfIn PDF document text
    • https://www.delaneyllc.com/ckfinder/userfiles/files/42740023396.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/kusowafufuniv.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/56296965152.pdfIn PDF document text
    • https://dakotaterritorydevelopment.com/ckfinder/userfiles/files/babalalodeji.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131925f23ec3---33361917034.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=mk+mobile+hack+2021PDF 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_off0000ef84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10796 19080 bytes
SHA-256: 7e293fa4201d5f582e3bad4cf2e4be9c6847ac1fba4a65231cd8e0235afa111b
font_02_sfnt_off00013957.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13957 10544 bytes
SHA-256: 38f68a26b5d460c1e2db73bee4e7eb013815bdecbe0382671a574dcc124ce803