Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d7cfff51285ee01…

MALICIOUS

PDF

87.3 KB Created: 2021-05-14 19:51:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: a92af1b9c1289cc42ddd30f9b7d9fd33 SHA-1: 2d55235d02521310d277431b95c3fac2d8f8bdd9 SHA-256: 7d7cfff51285ee01b789494ae89e09161b85fcefea1c983106cdc200d148d5b2
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous external links, many pointing to disposable domains and identified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but the primary malicious function appears to be the extensive list of external URLs.

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://leonvi.ru/strik?utm_term=mgma+salary+data PDF link annotation
    • http://baltika-trans.ru/tasizokipixeginufebona4oosu.pdfIn PDF document text
    • https://vutuwito.weebly.com/uploads/1/3/4/7/134713255/nubaw.pdfIn PDF document text
    • http://hermidkovo.info/xosubemhjuee.pdfIn PDF document text
    • http://ingmijn.com/85968116126t0k7f.pdfIn PDF document text
    • https://nerukime.weebly.com/uploads/1/3/1/3/131379394/tabinonokoweniw_bibupo.pdfIn PDF document text
    • https://bagolisenavela.weebly.com/uploads/1/3/4/4/134496394/wojagedubasuta.pdfIn PDF document text
    • https://seruvukajobal.weebly.com/uploads/1/3/4/4/134479042/6887439.pdfIn PDF document text
    • https://zovarufegurer.weebly.com/uploads/1/3/4/6/134625168/defexapanifovamevez.pdfIn PDF document text
    • https://kazowotamije.weebly.com/uploads/1/3/4/0/134012594/zizuzi.pdfIn PDF document text
    • http://soldatskaya6.ru/411957306748hv3q.pdfIn PDF document text
    • https://nipufosuvomabuz.weebly.com/uploads/1/3/3/9/133999137/8118394.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/1211df03-4742-448b-bff9-32881154cde1/is_there_a_print_edition_of_wsj_today.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/87aadc53-7bf4-4931-8061-3baf2071e3e2/how_to_rap_fast_without_breathing.pdfIn PDF document text
    • https://46c19374-600d-43be-a5f2-d8bf07c6fddf.filesusr.com/ugd/cc94a4_69739cb3ca12470db5647e3fddbf5163.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/ginutu/udi_818a_battery.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6168e21d-56bd-49ed-8b4b-36396389d75e/yard_machine_snow_blower_wont_turn_over.pdfIn PDF document text
    • https://71e5fc8e-cc9a-4633-96c3-2c70acd464d0.filesusr.com/ugd/f08e01_66af977571b243909dcdb8c4b2deddfe.pdf?index=trueIn PDF document text
    • https://56076a71-1b70-41e8-afe1-d547c394b4ee.filesusr.com/ugd/ab0d05_ee123acff87542f686cbe7e27377b57e.pdf?index=trueIn PDF document text
    • https://1de4b56a-3309-4767-83a2-f1bb1ea7c594.filesusr.com/ugd/a6e5e9_134e3f83239c4d07b1ac16307ae11dab.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a8173c6-bb8f-4585-bcc4-4d1450fc0f99/how_to_crochet_a_hat_with_magic_circle.pdfIn PDF document text
    • https://18574fdc-dbe8-4f24-a3f7-ab3d6ff540e7.filesusr.com/ugd/d45bfa_e8e2d0c882814e9cb003bba9145a0fbb.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lezopobigeza/83953636581.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/29945b25-2ded-4654-8493-10a8985af4de/large_printable_map_of_new_york_state.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_off000115d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115D9 5252 bytes
SHA-256: 8c55fd724665d3bb71e236c20a95c9fb17fb357c8f35fbece4ecbb460898b9fe
font_01_sfnt_off000127b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127B0 11224 bytes
SHA-256: 2b4ce475209ffa3a00024662e447f09554584c115e22055f8d356fdaaae0e9a5