Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5ef04ec8522f7a8…

MALICIOUS

PDF

77.1 KB Created: 2021-04-02 12:51:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: e607ada86ef76b52078e56e3430d19db SHA-1: b49b8c18bf5e3975b243f1dd09b9e2a4b2268e5b SHA-256: b5ef04ec8522f7a8420ad03ba0b03c0f400e94ea0e2e422f0db41a13e2599f84
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a mass of external links, identified as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or SEO manipulation. The presence of numerous external URIs suggests an attempt to direct users to potentially harmful websites.

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://zajinet.ru/wix?keyword=equal+groups+multiplication+worksheets+year+2 PDF link annotation
    • http://nuwojukow.mygamesonline.org/pmay_clss_application_form.pdfIn PDF document text
    • https://bamutemo.weebly.com/uploads/1/3/2/6/132681362/1b55548a0b0f41.pdfIn PDF document text
    • http://uscarins.info/xowuxibixafifeparixoxuboh5a0a.pdfIn PDF document text
    • http://balifruit.com/jadipesezovovetpyt7g.pdfIn PDF document text
    • https://lomasegikuporot.weebly.com/uploads/1/3/4/8/134846826/7855792.pdfIn PDF document text
    • http://xakaderinetatu.mygamesonline.org/xarikorekam.pdfIn PDF document text
    • http://jinevul.mygamesonline.org/gibetit.pdfIn PDF document text
    • http://getfreecreditreport.info/zivitadanisc6m.pdfIn PDF document text
    • https://vaxujorukub.weebly.com/uploads/1/3/1/0/131070318/9668502.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5f75e21-b3a6-4f33-a61f-1f970d2a7382/zagg_keyboard_ipad_air_2019.pdfIn PDF document text
    • https://5457524e-bace-410a-9ce7-c8d8bc0eedea.filesusr.com/ugd/f0ffd0_2b5120a79ba74cac867a3c34f6196863.pdf?index=trueIn PDF document text
    • http://suduxegowur.onlinewebshop.net/how_long_does_it_take_disability_determination_services_to_make_a_decision.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdaa757a-d4d1-4827-8632-b3bc39a423d9/what_is_the_meaning_of_the_word_computer_monitor.pdfIn PDF document text
    • http://zejibanunepi.myartsonline.com/55101384225.pdfIn PDF document text
    • https://c6506652-bf5e-4f52-be36-03dbfaede22c.filesusr.com/ugd/f74919_fc5f5aca4129444f8c75e21b7e28e0c8.pdf?index=trueIn PDF document text
    • https://db7841a4-af10-4990-a2be-f084cd4acbf6.filesusr.com/ugd/e3c460_40477e99c2db4c619b02a704386ddf3f.pdf?index=trueIn PDF document text
    • https://11f44e1d-c86f-4be6-baa1-90970e7c24f5.filesusr.com/ugd/a298ce_f66a6c00bd784b9ea42e705e2b783fc3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a661a77c-072b-4f5c-9ed6-b93dc7f86d63/61769513208.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a473ac68-9f3d-43f9-9c1a-1f93e05a6a19/88738721441.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/91d60648-95ba-4029-83d1-511040823b9a/augmentin_875_mg_for_uti.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_off0000ed9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED9D 5820 bytes
SHA-256: 10a59dc2b368a73e0c21f05d0ddca23506eee7b79a80cbc6c6dac6e49294b175
font_01_sfnt_off00010167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10167 11048 bytes
SHA-256: 3ca98e265e11a0a708dc467fb79a0496c24770e754b4c1386d48d79fe6241f0b