Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8be739137c5201d…

MALICIOUS

PDF

83.1 KB Created: 2021-09-13 22:25:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ab849398a98835e9d1bd4f46f8970dd3 SHA-1: be7179cbc037fb2c68f99184e676de157f6c65df SHA-256: b8be739137c5201d04d40db267fedb86ad1d6f72c83f26714413b2e537fe88db
126 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. The document contains numerous external links, with one heuristic specifically identifying it as a link farm on disposable hosting. While the document body is heavily obfuscated, the presence of multiple URLs suggests an attempt to redirect the user to potentially malicious sites for phishing or further malware delivery.

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.fred-robin.com/ckfinder/userfiles/files/61430574446.pdf In PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/44260370178.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/gozuze.pdfIn PDF document text
    • https://botroul.be/uploads/48207366390.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/91635141284.pdfIn PDF document text
    • https://wodepcb.cn/uploadfiles/files/19247694743.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/27948484820.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613215faeeaeb---59806008226.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/47900321322.pdfIn PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/tesin.pdfIn PDF document text
    • http://phubozena.pl/userfiles/file/88700778031.pdfIn PDF document text
    • http://newkontakt.ru/userfiles/images/file/fulosujumawewobu.pdfIn PDF document text
    • http://xn----7sbev0bhje.xn--p1ai/images/news/file/60309030517.pdfIn PDF document text
    • https://www.netcorp.hu/data/editorfile/rinowoteliruwikexojala.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f590b82a78---zugazoj.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210908155412.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/dejevejexe.pdfIn PDF document text
    • https://s-serviss.lv/userfiles/file/negojazidino.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/7145040910.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/22090870920.pdfIn PDF document text
    • http://mq-water.net/upload/79252261050.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/lukanuwijoxinoji.pdfIn PDF document text
    • http://canshu.dlzj.net/upload/files/20210913090739162789.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=battery+health+check+android+appPDF 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_off0000e071.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE071 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f888.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF888 10700 bytes
SHA-256: acece879001c6295ba57789fbd4b1b1c1eb8a66acd7e06963df8978f619849de
font_02_sfnt_off0001110e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1110E 17384 bytes
SHA-256: 6c333c0076887a2b11e401ce3f1ede4ecd66cd9dd9253f421ec553bde8abe721