Malicious PDF — malware analysis report

Static analysis result for SHA-256 f972ae90bc74f881…

MALICIOUS

PDF

73.7 KB Created: 2021-09-28 13:56:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 26d5d7ef70f67aeda329f43463ca3742 SHA-1: 422aa7fcef56c15b7bbc259d0c9574f1d7c80f7c SHA-256: f972ae90bc74f881a9932059532b035d85c9a945717892bc74512cd378d290e9
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan variant. It contains numerous embedded URLs, many pointing to suspicious domains, and exhibits characteristics of a link farm, suggesting an attempt to redirect users to malicious sites. The `wkhtmltopdf` authoring application is noted, but no specific scripts were extracted to detail further execution or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://087334211.kad.tw/kads/ckfinder/userfiles/files/mizawe.pdf In PDF document text
    • http://lokalsport.no/userfiles/file/30663041895.pdfIn PDF document text
    • https://27061010.com/uploads/files/202109100007552939.pdfIn PDF document text
    • http://boki.hu/editor_up/dutonisalasagapomosisil.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/tupuwekedogoti.pdfIn PDF document text
    • https://ms2oke.com/contents/files/94681063572.pdfIn PDF document text
    • http://chelseacarpet.com/ckfinder/userfiles/uploads/tarozabikapa.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///44231460977.pdfIn PDF document text
    • https://rrhh.fronteraliving.com/imagenes/contenidos/files/70011300730.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/kilufobemefuliwagenameme.pdfIn PDF document text
    • https://il-gusto.com/images/file/lagivudemis.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612f94eeb5b00---sekil.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/13679801011.pdfIn PDF document text
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210904040115.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210916214619.pdfIn PDF document text
    • https://www.tyrtaios.gr/ckfinder/userfiles/files/warup.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/menesaromoxefivejovarifoj.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/marasaguvinegejut.pdfIn PDF document text
    • http://hotelclinton.it/userfiles/files/fuwivuwagiguvuxi.pdfIn PDF document text
    • http://vvk-wiedermann.at/userfiles/file/20122057467.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/84604433176.pdfIn PDF document text
    • https://kompaspt1.com/contents/files/50804349519.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=black+ops+2+free+pcPDF 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_off0000b67a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB67A 10444 bytes
SHA-256: a7a0e15157c854c2b64e96142cadc520b19947f8693700047b5d5de3084bd13c
font_01_sfnt_off0000ce6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE6F 19544 bytes
SHA-256: 72cef43a3d9c21915482255d546ad630a96e771cd244db7d9e2bf200d8c3122d
font_02_sfnt_off00010104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10104 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1