Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4c4d0dd33855b48…

MALICIOUS

PDF

74.1 KB Created: 2021-06-08 19:54:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b937ad5435d2c21cf221c97953e8d2c4 SHA-1: 6656276b785071af1b8a6157fbd5cd3411c48778 SHA-256: f4c4d0dd33855b48ac018d5cc5a72203ba504bb122d282fb1c52b17b0163ece0
186 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm and by a machine learning classifier as malicious. It contains numerous external links, many pointing to disposable domains, indicating a likely attempt to lure users to malicious sites. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports this assessment. No scripts were extracted, but the presence of embedded URLs and the link farm structure strongly suggest a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/123?utm_term=vcenter++log+bundle PDF link annotation
    • https://fekujerixotose.weebly.com/uploads/1/3/4/8/134896765/kunefetinonijaf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393362/normal_60636ceeb795f.pdfIn PDF document text
    • https://radalumimobexod.weebly.com/uploads/1/3/5/9/135957078/2362852.pdfIn PDF document text
    • https://sixapinipuso.weebly.com/uploads/1/3/1/3/131384402/meserovofupoxokobaj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403404/normal_603ea003b0cf5.pdfIn PDF document text
    • https://mivebomuponi.weebly.com/uploads/1/3/1/3/131398008/vapos_xemubewale_mazefagato_mejezozexisuw.pdfIn PDF document text
    • https://fibepuranes.weebly.com/uploads/1/3/4/0/134041348/ff5d34721d7.pdfIn PDF document text
    • https://tuvonozesafuk.weebly.com/uploads/1/3/4/6/134600303/jagitajufiza_boxesawon.pdfIn PDF document text
    • https://duveniwapawas.weebly.com/uploads/1/3/4/2/134265961/bakib.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488339/normal_602c69debdfc5.pdfIn PDF document text
    • https://benarejara.weebly.com/uploads/1/3/1/4/131407695/416cf.pdfIn PDF document text
    • https://kofutisidizeb.weebly.com/uploads/1/3/1/4/131437743/mowasepefujivim.pdfIn PDF document text
    • https://jilefufut.weebly.com/uploads/1/3/4/1/134109271/pepun.pdfIn PDF document text
    • https://rivagenelozoro.weebly.com/uploads/1/3/4/6/134680428/ruwimexekaka-jisowepobufedo-fetamuzulejej.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393625/normal_601244a8bd745.pdfIn PDF document text
    • https://guvavibigedufos.weebly.com/uploads/1/3/4/8/134855984/fuxugogedomixom.pdfIn PDF document text
    • https://kapekutom.weebly.com/uploads/1/3/4/4/134437999/88b6625.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/e51dcb62-3003-4bdb-b3ad-d030f6a5ee87/fevebepibatuv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd9cdcf8-490f-4b87-867c-bc4aa3b34201/retegakobufupivob.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_off0000e6dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DC 4824 bytes
SHA-256: eb3b9acf89e92b215ddf79b74ded584371878f68d385d4279ec47ed39bdf5777
font_01_sfnt_off0000f755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF755 10572 bytes
SHA-256: 2f5ae05fb64dc742f809ba6e57d6df7db266f10eaf2734cf8b141218011ffb63