Malicious PDF — malware analysis report

Static analysis result for SHA-256 87da134bb88a28f7…

MALICIOUS

PDF

79.5 KB Created: 2021-04-26 15:45:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: e4c662813acfa03da591787d9c79db7d SHA-1: 1648c6f7278995baecd54e60c7a9cd19e3546bd0 SHA-256: 87da134bb88a28f7ceb1e548c24864b11d9d6cd0951111194dd018fbd9c62300
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-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://midufefew.ru/strik?utm_term=best+linux+distribution+for+beginners+2020 PDF link annotation
    • https://cdn.sqhk.co/gukisafuw/gigdjda/bazikiluvaki.pdfIn PDF document text
    • http://widonatozeg.mypressonline.com/jemibuvu.pdfIn PDF document text
    • https://pazerutafu.weebly.com/uploads/1/3/5/3/135392620/lugubenapux-limer.pdfIn PDF document text
    • https://lanekugufer.weebly.com/uploads/1/3/5/3/135351315/tedijisova-zipapegap.pdfIn PDF document text
    • http://sufawevugut.mywebcommunity.org/brevent_piste_map.pdfIn PDF document text
    • https://jenifamizoj.weebly.com/uploads/1/3/5/3/135319667/nofefuvepi.pdfIn PDF document text
    • https://cdn.sqhk.co/bexefoboxevi/0hgEgfo/samsung_push_service.pdfIn PDF document text
    • http://rejawulomov.mywebcommunity.org/javerenuzolaxez.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427105/normal_6057af9178d5d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475739/normal_601de9d36f96c.pdfIn PDF document text
    • https://rodawuliwunugen.weebly.com/uploads/1/3/4/4/134490897/2087057.pdfIn PDF document text
    • http://zapitexidij.mypressonline.com/gofamerovomolajebalasozi.pdfIn PDF document text
    • http://rixuliketasaban.mywebcommunity.org/70850667383.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5e54d98c-4257-4cc7-9010-48f3df296eb2.filesusr.com/ugd/05240c_6cff95b49af34559825e86659fabe652.pdf?index=trueIn PDF document text
    • https://e20d271a-53e3-41f9-9180-d6cd5f9fd148.filesusr.com/ugd/6cfc61_1c447b29db014f3bb15fe099517bc498.pdf?index=trueIn PDF document text
    • https://089130c0-62ae-4bf1-a93c-656440fe8451.filesusr.com/ugd/738632_88c180f281a846959516901e3476d37b.pdf?index=trueIn PDF document text
    • https://e05653fc-386e-4c8b-889d-738aee72c63e.filesusr.com/ugd/62421a_918f6fe4bea04881a161fc7e26f6be28.pdf?index=trueIn PDF document text
    • https://34570882-574e-4d25-8c0e-d8b9b6c2967f.filesusr.com/ugd/cb2bed_87235cab417e45978191a06c4f126988.pdf?index=trueIn PDF document text
    • https://6e37e838-c278-4d46-baa9-25b8497af200.filesusr.com/ugd/fbcb80_ee9c11b71886452fac70e1cdc9c89d63.pdf?index=trueIn PDF document text
    • https://8d40832c-2e2b-4284-8151-bb35a16d80ac.filesusr.com/ugd/05d014_f0a285750fcf4d4bab8734b38d8f2f45.pdf?index=trueIn PDF document text
    • https://3c8197b3-f999-4f29-b3da-fbdfea3dbf34.filesusr.com/ugd/0047a4_541a5646a8b448ba96282d92896893a2.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ebee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEE 2900 bytes
SHA-256: a28fcc4ba65d8171a55e8b87d646ac5d1dd213f66ab2b0026fd39e5ca5d32d1a
font_01_sfnt_off0000f630.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF630 5396 bytes
SHA-256: 5237944d50381ce5ba7af13ba3c5c0cadedee4f0281f609665dad8c66441c468
font_02_sfnt_off000108a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108A7 11092 bytes
SHA-256: 1be20819346fc35ba75d0a090ffb9ff8b9a3b85aaa8cad1dc8bad48d68b0b9cb