Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf535f036e52fee7…

MALICIOUS

PDF

75.4 KB Created: 2021-03-08 19:37:15 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: b5178b96edf2738137a82bf0a39babb2 SHA-1: 2bccc429982f4e335e9c91e9da20ce8e0e4072a3 SHA-256: cf535f036e52fee72cdebbe22a6cf833a4368103e6fbfc5a0b68a993450f47da
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to disposable hosting and appear to be part of a link farm. The primary URL, 'https://xajibur.ru/award?keyword=vce+exam+timetable+2020+pdf', suggests a lure related to exam timetables. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution via these links.

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
  • 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.
  • 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://xajibur.ru/award?keyword=vce+exam+timetable+2020+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4477379/normal_5fe5f69b7a793.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389090/normal_6019c1b2485a6.pdfIn PDF document text
    • https://cdn.sqhk.co/zalivelo/aighdcG/galuvokabopaxel.pdfIn PDF document text
    • https://cdn.sqhk.co/finulepaf/egdeUij/29472181509.pdfIn PDF document text
    • https://karawabinu.weebly.com/uploads/1/3/1/4/131453718/zuzajubumoguvazatofa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469623/normal_6034544ab9749.pdfIn PDF document text
    • https://zokupirijega.weebly.com/uploads/1/3/4/0/134000213/9731420.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380379/normal_6043356e78cae.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371788/normal_5fe69f8c249eb.pdfIn PDF document text
    • http://pajiweputuniwas.iblogger.org/konsep_pendidikan_islam.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492880/normal_5fea3913bdd21.pdfIn PDF document text
    • https://zawiwiguxasawum.weebly.com/uploads/1/3/0/7/130739629/rubipupojakasal_mixegopewix_zavewe_vawokizaweges.pdfIn PDF document text
    • https://talurepif.weebly.com/uploads/1/3/4/6/134603846/pajomilanuwawarasi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461761/normal_6028f40e3a1d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463552/normal_5fd67ecfc32a8.pdfIn PDF document text
    • http://gigogon.22web.org/close_up_c2_answers.pdfIn PDF document text
    • https://cdn.sqhk.co/waxipefimafa/1rBighy/38543938994.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://febagilelefejen.epizy.com/dunkin_donuts_munchkin_nutrition_info.pdfIn PDF document text
    • https://16cc4848-9a85-487f-bc1d-da55f68f8448.filesusr.com/ugd/dcf86b_00b7f700c37b48b6bf3d8cc6d20f0d2b.pdf?index=trueIn PDF document text
    • https://69f6cc44-9198-4e41-bafa-43503dba92bf.filesusr.com/ugd/dec231_03b3ad6b2bda4431858df031f61d095a.pdf?index=trueIn PDF document text
    • https://fac30f9c-1bc3-4ff6-ac40-7ced1d2a170b.filesusr.com/ugd/3b7182_3b0983c431124d8caf42ac78a5899595.pdf?index=trueIn 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_off0000ec1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1B 5472 bytes
SHA-256: efd9626398122b4958bd3fd56cfb86bb9e97b898b621c1192fcca24e5ec4eb00
font_01_sfnt_off0000feb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEB6 9936 bytes
SHA-256: bc57aef458b82cac27a5b16d1065678b86446bad326ef1fab5335c06550d2ee0