Malicious PDF — malware analysis report

Static analysis result for SHA-256 7175c5257610871f…

MALICIOUS

PDF

76.1 KB Created: 2021-03-16 08:10:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 85124fcf4ee32cb82c7e67bdd6bee259 SHA-1: 43dd4bb0b7992a94affcb2a866715924cdf7112b SHA-256: 7175c5257610871fa0dc11818b1f902e170df94cebb5355e13447257eefac20c
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a ClickFix social engineering attack. It contains an external URI pointing to a suspicious domain, vilenefex.ru, which is likely used to host or redirect to a malicious payload. The document body is heavily obfuscated, but heuristics indicate it instructs users to execute commands, a common tactic for bypassing security measures.

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
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://vilenefex.ru/aws?utm_term=why+are+my+pc+speakers+buzzing PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4495264/normal_6030087740a67.pdfIn PDF document text
    • http://fetesitomer.mygamesonline.org/army_pt_formation_reddit.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458633/normal_601dc529c8226.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456132/normal_603d8e37796d1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392474/normal_60173fcbc8ff8.pdfIn PDF document text
    • http://fivadoguna.medianewsonline.com/nupaw.pdfIn PDF document text
    • http://fadulifakibul.medianewsonline.com/39497307570.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391605/normal_60401ecf9d46a.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/559fd325-f18a-4be5-bf36-6a7f4365c35c/ring_keypad_blinking_green_battery_light.pdfIn PDF document text
    • https://56a7be67-7dca-40da-a973-69ad719fb73b.filesusr.com/ugd/fedf23_0b289d43b336448f8a90e71b2af71e05.pdf?index=trueIn PDF document text
    • https://f200304d-316b-45a9-b05c-680123ec6d1a.filesusr.com/ugd/aad1a2_1bad018705934acdbd8836ae84475c87.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/74936d1a-b56b-487c-bb4d-4968b5fa6878/first_alert_smoke_and_carbon_monoxide_alarm_keeps_chirping.pdfIn PDF document text
    • https://f6e2a16f-d004-42cd-8f17-0463e090774c.filesusr.com/ugd/c70c35_1326a9c57bb94446be4f51f3ed835feb.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e04c992-e71c-49af-bfb1-1afee6052240/doxuviwa.pdfIn PDF document text
    • https://510adc33-753b-44c0-977e-8d34da8fcdd4.filesusr.com/ugd/5f4192_4ff1f17a8b7a49f9a8f95d58455b212a.pdf?index=trueIn PDF document text
    • https://a815f367-2516-4b88-9496-eed07d5c1eb7.filesusr.com/ugd/665c20_c85639948ecb4527808d4297210334d9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2571a1ec-a921-4e53-9957-bffcefc5c798/how_much_weight_can_a_2017_nissan_pathfinder_tow.pdfIn PDF document text
    • http://tipokeviti.atwebpages.com/pebemodufomowenonejapekef.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3981591-aef3-4933-b396-a3d36bae6681/44900748406.pdfIn PDF document text
    • https://e61e9f85-32c5-4861-9fd4-b89109084c35.filesusr.com/ugd/2e4eb4_e831310a1bd047709d682067f5551946.pdf?index=trueIn PDF document text
    • https://2061f665-9309-41a6-981d-137229ee7e60.filesusr.com/ugd/eb2fe6_719dbd99916b461f83607e1a7c401b59.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA56 5684 bytes
SHA-256: a5f8ef4be9697871a4417d2ea6c11f132bddba5550d90f461b1073e626c3c64f
font_01_sfnt_off0000fd9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD9B 11064 bytes
SHA-256: 691da150a19619e5e351b2120d5ea4a5f53a81c832a0385eeaac44d13acb1732