Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8756dd15f6bb077…

MALICIOUS

PDF

81.2 KB Created: 2021-04-02 16:30:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: d2a8950e69d97493432b4f1040ff1256 SHA-1: 7ec22300f01b3808f1300395a8e2b9a1424453a8 SHA-256: a8756dd15f6bb077ac0c238ad7971db8e23e3a225e5f19219861c5e5afdaa24e
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://jumiwimov.ru/123?utm_term=ciencias+formales+ejemplos+yahoo PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4408330/normal_6018633937ed4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419192/normal_604aa5080d82e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417221/normal_605bdc3cea2e2.pdfIn PDF document text
    • http://nexofozupugasi.mywebcommunity.org/what_does_central_processing_unit_mean_in_computers.pdfIn PDF document text
    • https://jegesasep.weebly.com/uploads/1/3/4/5/134502647/falufeguto-lepiguwo-fomosotow-boxitejibomumum.pdfIn PDF document text
    • https://fodakapi.weebly.com/uploads/1/3/1/6/131637942/fovokibekap_negeninomu.pdfIn PDF document text
    • http://lezobul.medianewsonline.com/easy_ketogenic_meal_plan.pdfIn PDF document text
    • https://didukomam.weebly.com/uploads/1/3/1/8/131857465/5344415.pdfIn PDF document text
    • https://wemezixogasowed.weebly.com/uploads/1/3/1/6/131637562/xanijufik_zuripijunarogo.pdfIn PDF document text
    • http://xonigej.mypressonline.com/leroxejezexujot.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417315/normal_6034ddac6f3b9.pdfIn PDF document text
    • https://terodovob.weebly.com/uploads/1/3/0/7/130776228/tamepige.pdfIn PDF document text
    • https://weromosamewose.weebly.com/uploads/1/3/4/2/134265498/fewileki_jarebijid_zuxavupulozi_zakefunituzo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://11e0ccb5-01dd-4757-ae93-f6f3b4f5ca32.filesusr.com/ugd/1a2ce6_8385ec3051d040e592c123faa832c0e2.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/falevi/tuwal.pdfIn PDF document text
    • https://s3.amazonaws.com/livivuvuwugeb/89885720895.pdfIn PDF document text
    • https://s3.amazonaws.com/farokof/faxizediduzezobipa.pdfIn PDF document text
    • https://5b0e1d79-1acc-45ba-a965-31015372eee8.filesusr.com/ugd/67f5f7_7d60c7c48fbd48928dd350562eddef1c.pdf?index=trueIn PDF document text
    • http://gitodake.myartsonline.com/society_bye_laws.pdfIn PDF document text
    • https://6e8b94c7-278c-4a65-9c30-8d61c93a8f31.filesusr.com/ugd/9ff9b8_1f2bb1d191184a119f679cfae1fa3142.pdf?index=trueIn PDF document text
    • https://e6f9d1db-9bad-45ba-a188-0e8e378e8087.filesusr.com/ugd/99b222_8859ce537ab14537970951f55d5f42ad.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_off0000eadb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEADB 5164 bytes
SHA-256: a3197b3137f99929e422ac2e2a3cc4f1e5a795ae7ab65e95aeb7a0a04b714e75
font_01_sfnt_off0000fc3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC3F 13600 bytes
SHA-256: 9068f01cb0aade4e20ea142b404545a83a6b23b7a540565d51609c948251a70b
font_02_sfnt_off00012786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12786 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3