Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8b5feec0c80e685…

MALICIOUS

PDF

67.5 KB Created: 2021-02-13 08:51:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 8b6ef7a79fcdc6096cc933ce06534a04 SHA-1: 4fc69c11216d8c6c7073a17aeb86b4cc289b9307 SHA-256: f8b5feec0c80e68560f64ecdda773babe4623c020ff412818f55d26472297da5
244 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links pointing to external PDF files hosted on various domains, many of which appear to be disposable or associated with link farms. One critical heuristic indicates that the PDF links to known malicious redirector infrastructure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, and the document body was heavily obfuscated, making it difficult to determine a precise user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://yafferge.ru/wb?keyword=face%20blemish%20remover%20apk In PDF document text
    • https://zewadozodatigi.weebly.com/uploads/1/3/4/3/134337643/8461227.pdfIn PDF document text
    • https://cdn.sqhk.co/besiwowegin/jcBMZjj/63803092630.pdfIn PDF document text
    • https://vigoxanumevu.weebly.com/uploads/1/3/4/4/134466257/mapajurixisuko.pdfIn PDF document text
    • http://e-sparks.ru/exception_handling_in_java_pptu6av1.pdfIn PDF document text
    • http://biggymstoe.com/5008215842990v2q.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403130/normal_601f61b099e02.pdfIn PDF document text
    • https://zavigajigufuf.weebly.com/uploads/1/3/1/6/131637719/dulorokirula.pdfIn PDF document text
    • https://cdn.sqhk.co/beratinuga/fHhj9je/58033352166.pdfIn PDF document text
    • http://creditreportusa.info/fozetubadi5dx.pdfIn PDF document text
    • https://sixebujexe.weebly.com/uploads/1/3/0/7/130740217/vezedaja_matarosirezuxo_vuwuxawawelanu_luvamukexojuj.pdfIn PDF document text
    • https://cdn.sqhk.co/buvaboda/zhchfuo/3d_printer_amazon._es.pdfIn PDF document text
    • https://cdn.sqhk.co/tomubozes/jjbStjj/yeetus_the_fetus_birth_control_case.pdfIn PDF document text
    • http://nubupexajed.iblogger.org/48479656382.pdfIn PDF document text
    • https://cdn.sqhk.co/zojafatowulu/K3ihhcE/lucky_supermarket_senior_citizen_hours.pdfIn PDF document text
    • https://cdn.sqhk.co/rigizisojix/j3haidw/60292100807.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sojugixu.epizy.com/robber_bob_hack.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA35 5392 bytes
SHA-256: 73415cc28cbf0c01dfa7a9b641b958fd8f83ba754179e05567845e864cc55a5a
font_01_sfnt_off0000dc64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC64 10832 bytes
SHA-256: 25f1ac623ee388627f2a1e4ff04c47354af2d117597ef6d43672c2d9f47287bc

Open this report in the interactive analyzer, or submit your own file for analysis.