Malicious PDF — malware analysis report

Static analysis result for SHA-256 86a0139b2319656c…

MALICIOUS

PDF

76.9 KB Created: 2021-03-26 17:42:33 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 9832b5616c7d2f20a4fb42d702a6519f SHA-1: 9264105845d1902038f96e294396ad5bdf8e8e84 SHA-256: 86a0139b2319656c4ed0d5b3613e833903e7f600808846b74fdd92c36d2d3e56
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing malware. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, suggesting it was programmatically generated to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://pelibifir.ru/award?keyword=theories+of+administration+and+management+pdf PDF link annotation
    • http://jozipuvuwuzaj.mywebcommunity.org/technical_office_engineer_job_description.pdfIn PDF document text
    • https://ligavovifoma.weebly.com/uploads/1/3/4/5/134522072/71a78432.pdfIn PDF document text
    • http://jolidulikan.scienceontheweb.net/how_to_describe_touching_someones_face.pdfIn PDF document text
    • https://xisedemagi.weebly.com/uploads/1/3/2/6/132681548/7b7411c10837f.pdfIn PDF document text
    • http://nipijimosobolem.mypressonline.com/nemelaxoweguzatabo.pdfIn PDF document text
    • http://wiboratiraveguw.mygamesonline.org/athlean_x_program_download.pdfIn PDF document text
    • http://miribut.mywebcommunity.org/laroseze.pdfIn PDF document text
    • https://zetaxufonepijak.weebly.com/uploads/1/3/4/3/134353616/5610258.pdfIn PDF document text
    • https://zojegidaluvimov.weebly.com/uploads/1/3/4/1/134109086/judisazerag.pdfIn PDF document text
    • https://sawawinuta.weebly.com/uploads/1/3/1/6/131606003/dda5e909fdb7e2.pdfIn PDF document text
    • https://dafavazama.weebly.com/uploads/1/3/4/8/134893815/225c9b1.pdfIn PDF document text
    • http://tadajixilatu.scienceontheweb.net/tefopedopotamor.pdfIn PDF document text
    • https://nuxutesinof.weebly.com/uploads/1/3/1/4/131437012/dedinigala.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/833d3c35-fc9a-4d6f-b473-88cb0b6edd09/ok_cdl_air_brakes_practice_test.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b02012d9-217b-4100-84c2-b5975071c5b8/lg_306g_tracfone_master_reset.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e65bccc6-0788-4ed4-bcdd-7a13ffa2835d/yasar_nuri_ozturk_kac_yasinda_oldu.pdfIn PDF document text
    • http://kafotafuvodalix.onlinewebshop.net/neuropsychological_test_battery.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5617a042-f015-48d5-a506-5e8a37ef240d/6521813099.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1506e0e2-6317-43fb-ad11-5c95f7c2c15d/cant_help_falling_in_love_with_you_ukulele_cover.pdfIn PDF document text
    • http://nujebij.onlinewebshop.net/54872084814.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_off0000f24a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF24A 5372 bytes
SHA-256: 1524dff20c75b170dc79f4b35dd84cdab5d12cf7e7f8cff59cc766216c6029c3
font_01_sfnt_off00010466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10466 9716 bytes
SHA-256: a352968674f8da96c4a541d4394afcea074556bdc57650ce30e87471999ae5e8