Malicious PDF — malware analysis report

Static analysis result for SHA-256 c99ee8336b3c7afc…

MALICIOUS

PDF

72.1 KB Created: 2021-06-12 08:32:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 70608ad8b61a061a780f871f0f7f8492 SHA-1: ca32d8249c11d26b1feb6795f5c095a8635299fa SHA-256: c99ee8336b3c7afc6b2ee3354e49aa7630f26e3d4b361be6fd8e0fa21c848ddf
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, containing numerous external URLs pointing to other PDF documents. This technique is often used to manipulate search engine rankings or to distribute further malicious content, aligning with the Ingress Tool Transfer (T1105) MITRE ATT&CK technique. The presence of many external links suggests a potential initial access vector via Spearphishing Attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://archism.ru/pbw?utm_term=list+of+norse+mythology+gods PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4389823/normal_6006ac37e6671.pdfIn PDF document text
    • https://vavemome.weebly.com/uploads/1/3/4/6/134609594/sovunoxusi_metifugafudewa_nobaworunono_dotewigumirit.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413231/normal_5ffb03afdfb03.pdfIn PDF document text
    • https://kinefowez.weebly.com/uploads/1/3/5/3/135329655/d449878c.pdfIn PDF document text
    • https://birakegisepes.weebly.com/uploads/1/3/4/5/134597855/fopudibunor.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452852/normal_602f60ceb0ef2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483346/normal_606a1352cecd9.pdfIn PDF document text
    • https://kutofepiv.weebly.com/uploads/1/3/4/8/134898103/mimovugesojugu.pdfIn PDF document text
    • https://junimadegerozo.weebly.com/uploads/1/3/4/0/134096607/ruvifod.pdfIn PDF document text
    • https://takupomowemeb.weebly.com/uploads/1/3/5/3/135314116/3341351.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490754/normal_5fc5a7cc71325.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/b41a4dda-81d4-40ff-926c-22031ecafd7f/how_to_install_mini_wireless_keyboard.pdfIn PDF document text
    • http://wixumip.pbworks.com/f/bindaas_bengali_full_movie_mp4_download.pdfIn PDF document text
    • http://fibonilavi.pbworks.com/f/verb_dire_in_french.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a31cd68d-79e8-4267-932b-66f0e8af79da/93949918787.pdfIn PDF document text
    • http://wiwedano.pbworks.com/w/file/fetch/144423987/albert_camus_veba_zeti.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3651e3f-a5da-402a-8a4a-8d612a349a15/18029948343.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/df912461-05be-4975-948d-8c4ccd6b601d/tavexof.pdfIn PDF document text
    • http://juvupumanut.pbworks.com/w/file/fetch/144498816/one_click_root_mod_cracked_apk.pdfIn PDF document text
    • http://lakebimutep.pbworks.com/f/30533282131.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6eeb0fee-51cf-4076-bf52-fba376485f0a/35088523437.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8cdf90c0-c3dc-4c3a-98d6-4ee2a0f6f269/how_much_aid_does_the_us_give_to_pakistan.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_off0000dd3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD3E 5152 bytes
SHA-256: 3ebfedaf8eb3a45ab410678fcd0c7f0a385311bfc0fe2a938c316fa3ff076a19
font_01_sfnt_off0000eeab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEAB 10712 bytes
SHA-256: 47a4f156eae00203d3b7f5acf24c9539ef00702ff1ebe6e6813b7d42547adb2e