Malicious PDF — malware analysis report

Static analysis result for SHA-256 81fcd3667bac9a73…

MALICIOUS

PDF

74.5 KB Created: 2021-02-15 21:46:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 6c5ce41410aa94b591a3d8f48520fa14 SHA-1: e8638f0db87255339cc340e2a00caef06e3aef9f SHA-256: 81fcd3667bac9a7363b6cf6c60956e290cb4eae40f9335d31cf36afc288a1e1b
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by a machine learning classifier and ClamAV, flagging it as a phishing trojan. It functions as a link farm, containing numerous external URLs pointing to other PDF documents. The primary URL, 'https://bologen.ru/strik?utm_term=reloading+handbook+online', suggests a potential phishing or SEO manipulation tactic. The presence of many external links, some hosted on disposable domains, indicates a strategy to distribute content or redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://bologen.ru/strik?utm_term=reloading+handbook+online PDF link annotation
    • https://gisijenoxumo.weebly.com/uploads/1/3/1/4/131437849/letut.pdfIn PDF document text
    • https://cdn.sqhk.co/nakotuba/igdgjgf/gofuzikevezidirawovitutu.pdfIn PDF document text
    • https://jesofoxera.weebly.com/uploads/1/3/1/4/131407857/aaaa72469161422.pdfIn PDF document text
    • https://tuvukorop.weebly.com/uploads/1/3/1/8/131857527/3812310.pdfIn PDF document text
    • https://jafukixago.weebly.com/uploads/1/3/1/3/131380625/deloruvudodeke.pdfIn PDF document text
    • https://cdn.sqhk.co/wotezowedo/iijgejh/tugifasadamatujosupelidon.pdfIn PDF document text
    • https://cdn.sqhk.co/zifiguwosu/igf5ZJm/65898130551.pdfIn PDF document text
    • https://cdn.sqhk.co/dimusokobab/fJZbdif/doodle_halloween_2013.pdfIn PDF document text
    • https://cdn.sqhk.co/kugorazig/jaAjdhj/rorepuzizevabawitawo.pdfIn PDF document text
    • http://guvizaw.22web.org/answering_service_care_tukwila.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/tubupejevomo/alliteration_worksheets_grade_8.pdfIn PDF document text
    • http://nujobig.rf.gd/rexidine.pdfIn PDF document text
    • https://s3.amazonaws.com/babetafaperaxov/biztalk_server_2016_tutorial.pdfIn PDF document text
    • https://s3.amazonaws.com/ladiwuzetawedi/wififapaf.pdfIn PDF document text
    • https://s3.amazonaws.com/lotibabakuj/construction_company_profile_sample_format.pdfIn PDF document text
    • http://fibafewupo.epizy.com/74576190376.pdfIn PDF document text
    • http://ragigixo.epizy.com/60856990081.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d85c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85C 5024 bytes
SHA-256: dee846db69019a7419ebe15e407a48794ee878c7f25d949bfebd0a82c32cd699
font_01_sfnt_off0000e975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE975 10592 bytes
SHA-256: 3103f6fc51133392a04a233101c6aa3d020849e4fb49c21bfd1a72a94544b9a4
font_02_sfnt_off00010db9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB9 6076 bytes
SHA-256: 476a7f5ad4ca1955f8ba18bdbe3e5e1842c2b9bbc8bbe3e57526feecafd05314

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