Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a4dc4ab1cc2285c…

MALICIOUS

PDF

79.6 KB Created: 2021-09-18 18:02:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5bc056137a80bbc87d09acae120ff1e6 SHA-1: d667798b9aa37288f7f7db00d66d367ed8d31a43 SHA-256: 9a4dc4ab1cc2285c86194e2c98f420d7b06e2d197bdfa6e8a185705671742b51
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics suggest an attempt to redirect users to potentially malicious sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://haisushitogo.com/uploads/files/xiwugakokimab.pdf In PDF document text
    • https://arendic.cl/files/28270878568.pdfIn PDF document text
    • http://phanmemerp.vn/attachment/files/15019215835.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/jumugavipopuvixitajewo.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/sosakimusikozutoxi.pdfIn PDF document text
    • https://fier-forjat-valimet.ro/ckfinder/userfiles/files/sovagogizuwububofeteril.pdfIn PDF document text
    • https://mgc.to/sites/web/upload/files/24769256608.pdfIn PDF document text
    • https://acconpriti.com/ckfinder/userfiles/files/73459668317.pdfIn PDF document text
    • https://renesens21.com/ressources/upload/files/61419196977.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/51295660187.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/91517574313.pdfIn PDF document text
    • http://chinahongji.com/d/files/zibegowulatu.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/kemisuboluzoloda.pdfIn PDF document text
    • http://sk-uralstroy.ru/uploads/files/1153176735.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16137f234b094f---86714856984.pdfIn PDF document text
    • http://khiensa.com/UserFiles/File/81377679617.pdfIn PDF document text
    • http://ahzgbh.news-read.com/upload/files/bepowej.pdfIn PDF document text
    • https://komunalno-vrgorac.hr/files/95167410563.pdfIn PDF document text
    • http://prakseologia.eu/userfiles/file/56934565748.pdfIn PDF document text
    • https://sambelteri.com/contents/files/rasimejupop.pdfIn PDF document text
    • http://phuwangnam.com/user_file/file/wogufokumag.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/derafikusafivuzuw.pdfIn PDF document text
    • https://rosewoodcity.org/nbloom/fckuploads/file/zubafekogamurawurevavuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=best+app+for+iphone+emojis+on+androidPDF 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_off0000d2bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eacf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEACF 17440 bytes
SHA-256: 1a5fa3325b91f13f1d3874bbcfd5ceb9c5c3adc477743dd729578b56834d0bb3
font_02_sfnt_off00011806.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11806 10900 bytes
SHA-256: 17c674ee2ff70718d72b120a9e141b617e6248d82d1ba89855fd4bc981418f69