Malicious PDF — malware analysis report

Static analysis result for SHA-256 311cd0e687cd79bb…

MALICIOUS

PDF

97.1 KB Created: 2021-03-15 22:48:29 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 613b02cf133af6d6a91ea312adf23836 SHA-1: 56649a51c5831ea33b42f9dbdbdd5ba20b82f7cf SHA-256: 311cd0e687cd79bb92c030a96830268228391700484b9a453659571f3ac25c88
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 0.9992

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://golowaki.ru/strik?utm_term=what+does+the+communist+manifesto+say+about+the+bourgeoisie PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4404738/normal_5fef0ca549cd2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427274/normal_5ffbaf5e2da8b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465010/normal_6048db6a9e951.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455208/normal_6011fe15e83ad.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414161/normal_5ff25bd27b6fb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487632/normal_5fe9c771ca2a0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387412/normal_5fca8765ae65f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467586/normal_602fecd246ea2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391623/normal_600f151a10297.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422168/normal_60383b0e1cdb6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4500201/normal_5fe1ec2409a7d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369162/normal_5fe9b90ea8440.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4419003/normal_5fdf335abc178.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4472760/normal_5ffde3345be4d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502511/normal_602eac42e194e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6d23287f-a15b-43b7-8d69-700c0e01f504.filesusr.com/ugd/185c00_56137825b0fb4916a36e6eca1b0a77d8.pdf?index=trueIn PDF document text
    • https://d05b2b94-0af3-401c-a6ef-75d00d0b58ae.filesusr.com/ugd/3bca44_32d1d617ffcd4502897b492b687020d8.pdf?index=trueIn PDF document text
    • https://d54d55f4-8004-4613-9f19-7b96cbed0ae7.filesusr.com/ugd/ce4b32_3eccc57bd6364707a5678fdc2eba4603.pdf?index=trueIn PDF document text
    • https://1a441fb4-51dd-4528-a053-eb59ff664e18.filesusr.com/ugd/43d9d5_8a6475ebca0040e09e252976ce125292.pdf?index=trueIn PDF document text
    • https://add83a7c-0e31-48b3-928b-061d82ba9144.filesusr.com/ugd/205ae4_0931275790a64aa0947650255251a3d9.pdf?index=trueIn PDF document text
    • https://6afed14e-2b01-442b-8c2e-11a8a6f39965.filesusr.com/ugd/46a5ae_971080fff8304092b6a5fe6adf6dbb20.pdf?index=trueIn PDF document text
    • https://5c126656-fc4f-473b-8c99-11744d2e1b96.filesusr.com/ugd/abd8ec_439a52d21801484c92dc6ae7d1dc6727.pdf?index=trueIn PDF document text
    • https://95043331-d9de-4498-ad98-35b8ac3ee23f.filesusr.com/ugd/5740b2_b1a550e83070455593b3247c9504939f.pdf?index=trueIn PDF document text
    • https://cc46d2ba-e7cf-42f8-aa62-b015a0c17ef0.filesusr.com/ugd/d180c3_4b19d4b6f59945d5b9d5f93c22f0f46a.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013d8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D8F 5656 bytes
SHA-256: fa8ff2c15d8e1a2dcf649f6d0c016857d4e4fe842c0acb860560b530e8ba01d6
font_01_sfnt_off000150b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x150B8 11448 bytes
SHA-256: 1cca6ca5ed199e8d54ba99996f1e027a339e66799ec8bc45a3335d0ff538ec6a