Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6738e5a2da84109…

MALICIOUS

PDF

73.4 KB Created: 2021-03-01 06:40:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 3a7ee5c73164b74cb1a071439116eb69 SHA-1: b818143d32dcf67e482eb4e19541b4798d7d876c SHA-256: b6738e5a2da8410958630be761727f84e6dbc52e62275524cb0776ac0e466f98
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm likely used for SEO manipulation or to distribute malicious content. ClamAV and ML classifiers strongly indicate maliciousness, with the PDF_SEO_LINK_FARM heuristic highlighting the mass of external links. The presence of multiple external URIs suggests an attempt to redirect the user to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://zajinet.ru/strik?utm_term=ariens+engine+oil+capacity PDF link annotation
    • https://pefobasor.weebly.com/uploads/1/3/4/1/134131397/napiwikojenew.pdfIn PDF document text
    • https://degulula.weebly.com/uploads/1/3/1/0/131070998/lukivovejebeteramoze.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379961/normal_5fd1de281a9ad.pdfIn PDF document text
    • https://jajonugofetafis.weebly.com/uploads/1/3/0/7/130776034/bupusajut.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455179/normal_5fe609db5ed1a.pdfIn PDF document text
    • https://rawoxozuk.weebly.com/uploads/1/3/2/6/132695352/firagikofimu_dapikad.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4497079/normal_5fe09788878f2.pdfIn PDF document text
    • https://ponuxarazuzega.weebly.com/uploads/1/3/5/3/135328107/jeleja.pdfIn PDF document text
    • https://tejaxoxujita.weebly.com/uploads/1/3/4/3/134368030/diruzemazasom.pdfIn PDF document text
    • https://fejuzewe.weebly.com/uploads/1/3/4/8/134883228/e94f5921b8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417030/normal_5ffd113559e86.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454678/normal_5fd0a0fa8a679.pdfIn PDF document text
    • https://teraxumafelenug.weebly.com/uploads/1/3/4/7/134747654/6e915dfcea2f6af.pdfIn PDF document text
    • https://gulesome.weebly.com/uploads/1/3/4/4/134496781/jatobama-bukugajapuzam-bomup-dinulepoketawuk.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479226/normal_6032cc5d17516.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417213/normal_5fff94d01f1e5.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/bomupi/template_for_announcement_of_new_employee.pdfIn PDF document text
    • https://s3.amazonaws.com/migivewuwe/pentagon_shine_piano_sheet_music.pdfIn PDF document text
    • https://s3.amazonaws.com/vebogotexaf/walijetimemon.pdfIn PDF document text
    • https://s3.amazonaws.com/fopalew/3500531857.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_off0000e35a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE35A 5192 bytes
SHA-256: f38f6fc7e708a26dac22ecdf2a5ac805e85be672d82195737b0cf742d2b64095
font_01_sfnt_off0000f526.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF526 10224 bytes
SHA-256: 285ea1be8299018f1ed7d23c5d3e334f96b1c7fdae9da33e177b44c391466e3b