Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7685b6ca5f44630…

MALICIOUS

PDF

82.9 KB Created: 2021-09-19 17:27:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c4b80b4712167e9a05455fc475d8c58b SHA-1: 1e3acea94f62f4df11f302176c6e5b85e5312e2f SHA-256: b7685b6ca5f446305d1eec0eccee39a09b8d00d76ccc49227b388f26f80c2abe
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent. No scripts were extracted, but the presence of numerous external URIs points to an attempt to redirect the user to malicious content.

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 https://crysiq.ru/uplcv?utm_term=android+wifi+assist+turn+off PDF link annotation
    • https://poojaindiangrill.com/nbloom/fckuploads/file/xigoximomusokudak.pdfIn PDF document text
    • http://owop.challengersports.com/ckfinder/userfiles/files/wapokevidijude.pdfIn PDF document text
    • http://rqconsultores.com/userfiles/file/puruxoxevijiwixowivu.pdfIn PDF document text
    • http://doggystylzgrooming.com/admin/photos/file/jutamunudewulubirolu.pdfIn PDF document text
    • http://111-orte.com/testarea/cwsCMSlight/media/files/11398159057.pdfIn PDF document text
    • https://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/39568433552.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/23037951196.pdfIn PDF document text
    • https://sunsoftinfoway.net/ckfinder/userfiles/files/telizagoloxovati.pdfIn PDF document text
    • http://escalierdurire.fr/ckfinder/userfiles/files/panejomaxuvujozonesawez.pdfIn PDF document text
    • http://caopump.com/admin/userfiles/file/bizamaxinuxajovibunifegu.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/58839900250.pdfIn PDF document text
    • http://zzquansu.cn/d/files/16252333980.pdfIn PDF document text
    • https://maurinet.com/userfiles/file/tabenatosidojesewix.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/33266116259.pdfIn PDF document text
    • http://thehedgerowchronicles.com/ckfinder/userfiles/files/kuxadosozad.pdfIn PDF document text
    • http://forumcutuca.com/ckfinder/userfiles/files/tudizov.pdfIn PDF document text
    • https://eurotig.ro/file/63499271553.pdfIn PDF document text
    • https://ewt.cz/res/file/57331057487.pdfIn PDF document text
    • http://gardena.crazyrockinsushi.com/uploads/files/75592342503.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16143713202b89---nefudebifukaboromite.pdfIn PDF document text
    • https://dcoderesearch.com/uploads/61873209981.pdfIn PDF document text
    • http://boonfagrandhome.com/user_img/files/97861007348.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/87073055858.pdfIn PDF document text
    • http://safetruck.gr/images/file/56668036441.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff2125c2fd---sirenuwisipo.pdfIn PDF document text
    • 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_off0000dfc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC9 17896 bytes
SHA-256: f093aef3286f830897876ac768988db4c9d5c26531f9951c6cbb0da533782817
font_01_sfnt_off00010e08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E08 10336 bytes
SHA-256: 0557d9635125ff6dd4b369a743ef6235287e3512ab238fb1034c056a34f371de
font_02_sfnt_off0001258e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1258E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1