Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b81165ad951c04…

MALICIOUS

PDF

72.1 KB Created: 2021-03-26 02:53:23 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 02c4b8e25ae048e9b74a5bff33ade7e0 SHA-1: d7e15b4b0789122b19ffae9a16a36d75275f0e1f SHA-256: f8b81165ad951c04e65fe2dd7eccda8aa5ed88ae1575340c98425925117a9480
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains an embedded URI pointing to a suspicious domain, identified as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URI suggest an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jumiwimov.ru/strik?utm_term=2008+jeep+jk+rubicon+for+sale
    • https://tefovaxosu.weebly.com/uploads/1/3/1/1/131163863/f111e9f86.pdf
    • http://kokofiru.22web.org/capture_card_software_free.pdf
    • https://tabivivefevevu.weebly.com/uploads/1/3/4/8/134889686/fubasoworebe.pdf
    • https://cdn-cms.f-static.net/uploads/4388827/normal_6025a308eda6c.pdf
    • https://cdn-cms.f-static.net/uploads/4448126/normal_600fe34e9e436.pdf
    • https://static.s123-cdn-static.com/uploads/4484380/normal_5fffc2146b3a1.pdf
    • https://static.s123-cdn-static.com/uploads/4486221/normal_5fefde4299839.pdf
    • http://rexapeduke.66ghz.com/what_are_the_latest_coronavirus_numbers_in_michigan.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/bubeto/is_benzene_found_in_cigarettes.pdf
    • https://uploads.strikinglycdn.com/files/86261d17-78a7-4ae9-b3c1-35afe7813e6f/marketing_management_concepts.pdf
    • https://s3.amazonaws.com/gumagabu/d-link_dir-601_speed.pdf
    • https://uploads.strikinglycdn.com/files/d2c3c5d1-2b1c-4462-8c6e-1d81e596f784/kenuzotifokub.pdf
    • http://ruxopalivefe.rf.gd/how_to_get_soap_response_xml_for_a_web_service_call_in_c.pdf
    • http://xujekapowizi.epizy.com/zuwed.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dba1.bin
a702140c41b0a68586b391a782894b71959639bd08ac8dc7d12042196bb162fc
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA1 5664 bytes
font_01_sfnt_off0000eef4.bin
f975e5c3f613d478a3899514b9dcc3285fccdc5835f3e16676edab3b25845135
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF4 11052 bytes