Malicious PDF — malware analysis report

Static analysis result for SHA-256 5167fb920d437611…

MALICIOUS

PDF

73.3 KB Created: 2021-02-19 23:32:49 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 134f631647bae7934c78ff8644a37394 SHA-1: bab63d28c46c813295d8b9f429e80dd66c7c9cef SHA-256: 5167fb920d437611f86931733992cd8e7e76658cd075846dc242765b000a6708
244 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links pointing to external PDF files, a technique often used for SEO manipulation or to distribute malicious content. The heuristic firings indicate that the PDF links to known malicious redirector infrastructure and is part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • 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://crophysi.ru/wix?keyword=nefarian+boss+guide In PDF document text
    • http://pl50off.info/the_alchemist_code_global_news2lnu9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474985/normal_5fd126addc8c6.pdfIn PDF document text
    • https://sefewazugep.weebly.com/uploads/1/3/5/2/135293251/zenepur-sozabozuwakus-kitetugikijab.pdfIn PDF document text
    • http://remontvorot24.com/ind_safety_reporting_regulationskrdje.pdfIn PDF document text
    • http://axecheat8.xyz/84849159790ozowp.pdfIn PDF document text
    • https://cdn.sqhk.co/kegufamop/uhbidib/kuvorajebarixisa.pdfIn PDF document text
    • https://wabexerimib.weebly.com/uploads/1/3/0/7/130739061/xifoziso-wajapewob-jukuvuxo-muxisavirujit.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420604/normal_5fffb36497149.pdfIn PDF document text
    • https://jonomivebotuw.weebly.com/uploads/1/3/4/6/134683751/2c1bfe5f75a6b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421776/normal_5fd8317e06fba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373259/normal_602ada285d98d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388174/normal_5fedb0692352e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4443576/normal_5fd87a1999971.pdfIn PDF document text
    • http://giocodigital.fun/27884485917mmxva.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501229/normal_5fe9b6e0ed143.pdfIn PDF document text
    • https://cdn.sqhk.co/vanewano/TibEhhK/7511458579.pdfIn PDF document text
    • https://cdn.sqhk.co/xeposetuge/blljfjc/save_girl_child_essay_in_english_100_words.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406229/normal_5fe6942facaba.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475209/normal_600321b636b3d.pdfIn PDF document text
    • http://ses-paypal.com/imagery_in_romeo_and_juliet_act_4xreqc.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e38e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE38E 5152 bytes
SHA-256: 9ee06fa71c2f9dbb40ea2dc995aa11c7b7ceeed33ac52b44bb9f5c03e1d4d0b6
font_01_sfnt_off0000f529.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF529 10368 bytes
SHA-256: c15a5492a58e0e1aef011773a0fc2d13630affdf4ce304c404ef01820e15ecf7