Malicious PDF — malware analysis report

Static analysis result for SHA-256 a17f77b0730b4d85…

MALICIOUS

PDF

79.2 KB Created: 2021-05-08 22:21:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 273ebe3a5ceee34454463804464a44db SHA-1: 7c6ebc9460d51a5573982b1dc8d45ccb41a752ec SHA-256: a17f77b0730b4d85d5bfd35e0c8d9c8bedf6ee8db41aeafa86165af193f255d2
186 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a large number of external links, many pointing to disposable domains, characteristic of a link farm or SEO manipulation scheme. The presence of multiple PDF_SEO_LINK_FARM heuristics indicates a deliberate attempt to create a network of linked documents. While no scripts were explicitly extracted, the PDF structure itself facilitates the embedding of external resources, and the URLs suggest a potential phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://kuzutuzo.ru/strik?utm_term=war+horse+book+characters PDF link annotation
    • https://cdn.sqhk.co/nuvurero/cOPic7v/parisizafat.pdfIn PDF document text
    • http://sosutisokalelul.iblogger.org/16434035201.pdfIn PDF document text
    • http://nugawijuxuv.mywebcommunity.org/sotejox.pdfIn PDF document text
    • https://cdn.sqhk.co/rapigufagi/kCRUjga/36781389117.pdfIn PDF document text
    • https://cdn.sqhk.co/samivegin/ijfiigc/talking_angela_hacker_2020.pdfIn PDF document text
    • http://zugoruvupigit.iblogger.org/tetafa.pdfIn PDF document text
    • http://pokezokebawi.mygamesonline.org/8793581625.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370764/normal_5fccec7028542.pdfIn PDF document text
    • https://cdn.sqhk.co/mewoveri/eFgczYT/pulse_secure_force_client_version.pdfIn PDF document text
    • http://fibaxoxadomi.sportsontheweb.net/mowubenepozijutunekevo.pdfIn PDF document text
    • https://cdn.sqhk.co/nonuripot/icouja2/farming_usa_2_free_download_full_version.pdfIn PDF document text
    • https://cdn.sqhk.co/lisesemafo/fhhibgd/49206288279.pdfIn PDF document text
    • https://cdn.sqhk.co/gixobujikelu/BjhhgXU/evolution_definition_biology_bbc_bitesize.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478415/normal_60531c703e21a.pdfIn PDF document text
    • https://cdn.sqhk.co/woselukafo/bjjJUhb/jonerepotota.pdfIn PDF document text
    • https://cdn.sqhk.co/gofelaxes/QeVjihc/diaphysis_definition_medical.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371807/normal_6060c239e59d5.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6776ac3f-883f-499f-bc52-38dff818ec46.filesusr.com/ugd/969751_36f3e4956d21416696cec0121e628938.pdf?index=trueIn PDF document text
    • http://kokulokigebowow.rf.gd/accounting_cycle_free.pdfIn PDF document text
    • https://80f75f89-a1e3-4611-a0ef-7a704eb82da9.filesusr.com/ugd/0286dd_3abface795a84543b39c3684bb4d0a19.pdf?index=trueIn PDF document text
    • http://kelujisulajow.rf.gd/chemistry_notes_form_1_free.pdfIn PDF document text
    • http://felawikemuda.epizy.com/38533358196.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_off0000f7d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7D5 5072 bytes
SHA-256: e8cc3220fe15af718fe4edb85479b2892c52588426372a295d20d261c5b3d36a
font_01_sfnt_off00010923.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10923 10880 bytes
SHA-256: 027e038cdab9eb6c5b3e73abc8a94ec6dc71eab0e8170fd2164691e4b01d3089