Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7db9fe8bb1912f0…

MALICIOUS

PDF

81.6 KB Created: 2021-05-27 06:28:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: f2c9ffcec64d8c5437e0e721e2c4e569 SHA-1: 90b446707861cc52d056f2b3880c9d6e27bfcfc8 SHA-256: f7db9fe8bb1912f012b48303352ebf9c9080f80359c587854a115ca6fcd93794
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. The primary IOC is the URL used for redirection, which is part of a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://fokemale.ru/strik?utm_term=sistemas+electricos+de+potencia+stevenson+pdf+solucionario PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4501980/normal_5fdf11b8f3c90.pdfIn PDF document text
    • https://zizojatemizowen.weebly.com/uploads/1/3/4/0/134016780/kudobuna-zivazilat-buveb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382421/normal_6008953303b2f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4506063/normal_6007682579c3e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449616/normal_5fd3cd364347b.pdfIn PDF document text
    • https://rixodinek.weebly.com/uploads/1/3/5/3/135392020/dexafuwifoxafeloroli.pdfIn PDF document text
    • https://javesuput.weebly.com/uploads/1/3/0/8/130873829/e05bf7959e0d.pdfIn PDF document text
    • https://jajamavufivaz.weebly.com/uploads/1/3/4/2/134235884/7859433.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4455180/normal_5fedc39aca91d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483855/normal_5fdbda201d319.pdfIn PDF document text
    • https://zadujemerumid.weebly.com/uploads/1/3/2/6/132695269/2a638a.pdfIn PDF document text
    • https://wirejosesem.weebly.com/uploads/1/3/1/8/131856641/xuwapi.pdfIn PDF document text
    • https://zijevalejo.weebly.com/uploads/1/3/4/7/134770519/9cf3efc34d6f884.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490251/normal_601247bc4412b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489058/normal_605a61cf655a9.pdfIn PDF document text
    • https://kexazupaxi.weebly.com/uploads/1/3/3/9/133997339/1863277.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://uploads.strikinglycdn.com/files/ba2b5c0e-da5f-4a57-a3ad-2f33d0b1db34/vipoxasibipodurakaful.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ff5d7888-5e41-4c16-be1d-a6a78a5b56c2/bobomitagovo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b4133ab6-3340-482a-a22c-3bafef307040/10469424252.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a788004e-6dc0-4f7d-8163-72dd5fa0da69/venabezafo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5d1756ee-6fb4-47bd-b465-6f9c201d01fe/spacebattles_jumpchain_drive.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f334bf41-5b8a-4996-9880-c4f781f7bfc2/how_to_apply_vinyl_labels.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3bd82624-6033-4300-9b8e-bea489ee6b26/zozumixi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/83b0aed2-f206-44ad-8a85-c5a9712fbbd0/how_to_manage_adhd_without_medication.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3da409d-69f7-46a1-8fb9-53ede2207253/can_you_exercise_with_mild_scoliosis.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53D 5344 bytes
SHA-256: f066dc8bd6ca73642482c076cd519744eb36a44e176e8b56b00d666f15b2cbbb
font_01_sfnt_off00010747.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10747 10188 bytes
SHA-256: 1c2f6045ffe36debfd806353cd9631d784c809890f5d86a2168d44c2206b8fb4
font_02_sfnt_off00012a14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A14 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333