Malicious PDF — malware analysis report

Static analysis result for SHA-256 36c6d3cc2f089621…

MALICIOUS

PDF

73.4 KB Created: 2021-06-06 21:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 4543a2f9a8798feb0c42c2f695aae53a SHA-1: 059f893531ce67a649f2ae8f20bd73d79949e6be SHA-256: 36c6d3cc2f0896210cb5ffd7f7a41778a990db67cb23d575804ba8415a7e9f53
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 hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV and ML classifiers identified the file as malicious, specifically a phishing trojan. The embedded URLs suggest a potential phishing or malware distribution vector, although no scripts were directly extracted to confirm further execution.

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://ketchas.ru/pbw?utm_term=java+oca+8+programmer+ii+study+guide+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4389370/normal_5fce07765627e.pdfIn PDF document text
    • https://jasuxazej.weebly.com/uploads/1/3/4/8/134875243/papofonemirime.pdfIn PDF document text
    • https://gebusoju.weebly.com/uploads/1/3/0/9/130969184/ruxalemova.pdfIn PDF document text
    • https://ralirepiputup.weebly.com/uploads/1/3/4/8/134852471/sajijo.pdfIn PDF document text
    • https://zukodefikarux.weebly.com/uploads/1/3/4/4/134498552/dbada.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448743/normal_602445f118439.pdfIn PDF document text
    • https://jipaxebuperiw.weebly.com/uploads/1/3/4/7/134751602/4054110.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481994/normal_5ff76a6d026ea.pdfIn PDF document text
    • https://tebumozokafu.weebly.com/uploads/1/3/4/4/134471783/sokifebusosa-potomofuga-nadewur.pdfIn PDF document text
    • https://wawomageton.weebly.com/uploads/1/3/4/5/134584849/6ad94.pdfIn PDF document text
    • https://nafarusulewabol.weebly.com/uploads/1/3/4/5/134587722/fixuritoz-ponul.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/922b80bb-f1cd-4ef1-9339-67a24f60ffbc/luvukuz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e7ce6c09-3eca-42b9-81aa-49a71fa61f24/81477230263.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/314aac89-699c-4aa7-aac4-a5c9888cad21/netgear_ac1600_vdsl_adsl_modem_router_d6400_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/823c2e73-6738-40c5-a519-5f88411ffad3/all_the_bright_places_movie_quotes_capacities.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1b78f5a9-6b0f-4c63-b7a4-b9282b182e08/how_to_change_the_time_on_fitbit_charge_hr_2.pdfIn PDF document text
    • http://fevawigo.pbworks.com/w/file/fetch/144662247/82056988651.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1ba697b1-61cf-46de-9d5f-ad48f344a535/kreepy_krauly_legend_ii_manual.pdfIn PDF document text
    • http://poguvovuk.pbworks.com/f/what_caused_the_marshall_university_plane_crash.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e2eb5dbf-3142-4524-be4a-1445b19dc2e3/68443607184.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_off0000df46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF46 5788 bytes
SHA-256: bfffe8edae70cc1509199c1d4889b440331cb282341f2a7e895c8f15daa5da35
font_01_sfnt_off0000f2f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F9 10640 bytes
SHA-256: 763fa3776417ec754f18496cd4ced4baa05e6934b9b0084a61e9318a5da8be86