Malicious PDF — malware analysis report

Static analysis result for SHA-256 636f6bd2385bb10d…

MALICIOUS

PDF

82.0 KB Created: 2021-04-24 18:58:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: d1deb704e0d31b94c1c6a943ec071f6b SHA-1: 503ca145e840117e156db27ccadaa476e22c97c8 SHA-256: 636f6bd2385bb10d407485fc9d83398f1c32ebf4417c0e57a3a3824da674dc22
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

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://maypoin.ru/strik?utm_term=crucigramas+el+pais+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4385435/normal_5fe58c9642939.pdfIn PDF document text
    • https://xalakadumikimam.weebly.com/uploads/1/3/1/4/131437423/tubuwatupumutimeri.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384825/normal_602e1be99e8cd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423460/normal_601b4bb81e820.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377663/normal_604cf27491057.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4528915/normal_5fe962612b25e.pdfIn PDF document text
    • https://rukudigef.weebly.com/uploads/1/3/4/6/134642400/bimawa.pdfIn PDF document text
    • https://vokubopupabilu.weebly.com/uploads/1/3/4/6/134691430/mimepifevepawosedom.pdfIn PDF document text
    • http://characduwe.space/how_to_write_regression_results_in_apa_format7q5wk.pdfIn PDF document text
    • http://lofitner.buzz/siluxodurudakigexifekes4jaee.pdfIn PDF document text
    • https://belujewirozem.weebly.com/uploads/1/3/2/6/132681559/kuviw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468553/normal_60590947a1eb5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408336/normal_5fcd6c66c388b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d7ae471b-a447-437d-81b4-4e603f8679d9.filesusr.com/ugd/0a3240_54c13a30921c4c20bfeebf8ecac900c5.pdf?index=trueIn PDF document text
    • https://964beff5-d24f-450a-94e2-fa7e9faef44a.filesusr.com/ugd/61158f_29cd3ba7bf0d43b5aabee4967a8527e4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/futamo/70539146663.pdfIn PDF document text
    • https://cae2aa39-5014-47ec-b549-0fed73f36d02.filesusr.com/ugd/c8683e_e08568d0d9a74ab4b9c209076b9c18b6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zakunafu/burolevepoxidotexakuner.pdfIn PDF document text
    • https://66f9544f-8325-470d-a543-c07714603334.filesusr.com/ugd/4b2642_6d6f1da72a0d48c5b730e506ead68945.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/ziwuvijevo/shark_vac-then-steam_2-in-1_vacuum_and_steam_mop.pdfIn PDF document text
    • https://357b8bef-7330-4cfe-b31d-389db25c4d5a.filesusr.com/ugd/4c76bf_775f915f00dd4513a9d09275bd2204b5.pdf?index=trueIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000decf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDECF 5380 bytes
SHA-256: 056469e9917fbcb8babfdd96d0ae7e31f02841b99dd13d18e9d3fb7a684f8fbe
font_01_sfnt_off0000f0ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FF 15224 bytes
SHA-256: 6ad9be588de001e8213f6276659cdc14842667470a0b0422014bc686078dee9d
font_02_sfnt_off000120a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120A4 16952 bytes
SHA-256: 225c4eb3b687ffd836cc5e379663e63a8e66ea68ca8fdd00a6afaa0ce62cfbe8