Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba5cb832cabfdd50…

MALICIOUS

PDF

74.5 KB Created: 2021-06-10 11:27:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b1414c5beb4ce95ee4d17acb3ed3b732 SHA-1: 77c980c6b9b0a87359949a43c399bfa3a08633fe SHA-256: ba5cb832cabfdd50a8738d63c71139e31f9cc8628d409c6e942e9ed492db1f89
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of external links, many pointing to disposable hosting services, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for SEO manipulation or to distribute further malicious content via the linked PDFs. The embedded URLs and the nature of the link farm are the primary indicators of this malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://cructi.ru/pbw?utm_term=onbathu+kolum+song+mp3+free+download PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4419827/normal_601a9af44991e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390999/normal_605248e3ee908.pdfIn PDF document text
    • https://majozopova.weebly.com/uploads/1/3/7/5/137513286/gisagozopomim.pdfIn PDF document text
    • https://pizopivawot.weebly.com/uploads/1/3/5/3/135347149/kekadu-zitosorumib.pdfIn PDF document text
    • https://dewubixire.weebly.com/uploads/1/3/1/3/131398231/c06a01.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427499/normal_60610021bde3b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464052/normal_606aea1d0f5e7.pdfIn PDF document text
    • https://bavazaje.weebly.com/uploads/1/3/4/3/134335981/serovekivof.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4374976/normal_5ff8583e4de4f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4380230/normal_6006a8d9d598a.pdfIn PDF document text
    • https://fofijibub.weebly.com/uploads/1/3/3/9/133999799/wanudaposifilim.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393641/normal_5fe007a104c93.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408002/normal_60015b06b2243.pdfIn PDF document text
    • https://rodazikajoreme.weebly.com/uploads/1/3/0/8/130874285/dagepikefakurefawem.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418583/normal_6043e1b4df8ac.pdfIn PDF document text
    • https://nosisakapu.weebly.com/uploads/1/3/4/7/134773138/8781657.pdfIn PDF document text
    • https://bopexetijajab.weebly.com/uploads/1/3/1/4/131411078/9a8899a9.pdfIn PDF document text
    • https://kalepadakib.weebly.com/uploads/1/3/1/6/131637037/a7553f.pdfIn PDF document text
    • https://dijafujuzu.weebly.com/uploads/1/3/4/3/134369935/sofemilelo.pdfIn PDF document text
    • https://xovamiwif.weebly.com/uploads/1/3/4/0/134096018/9448665.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/135a64e7-2c38-4d14-ac63-b56ceccc19f4/71640904287.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b533fc4c-3ede-42fe-adec-3bcf697e848a/61583187129.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8c60f89-440b-4726-b91f-1de6cbbaacd3/bluebook_citation_generator_apa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6af61d3f-531c-4b4b-a278-aa0fc2933b81/brown_bear_brown_bear_what_do_you_see_synopsis.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_off0000e3ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3CE 5944 bytes
SHA-256: 5fad2f7923abbf616467f374df0798480fd7e6c65897a8f9a324d1eea385d049
font_01_sfnt_off0000f7e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E5 10744 bytes
SHA-256: 2f83c4d43ded1851215d46cf1a139d3f05463dfbce905470bb1d0d487dc8a1fb