Malicious PDF — malware analysis report

Static analysis result for SHA-256 7658425aae72a447…

MALICIOUS

PDF

79.1 KB Created: 2021-03-18 18:22:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 60d77ece535047c8fa3e0f0f573c9a42 SHA-1: af98e0b0d2ac57be305d57415b30192275c96ab6 SHA-256: 7658425aae72a4475c7add0576fc14051572dc93f4cae1e63048950b7b160718
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a link farm with numerous external links, many pointing to disposable hosting, designed to deceive users into downloading a calculator application. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the embedded URLs and link farm structure suggest a phishing or social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • 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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://crophysi.ru/strik?utm_term=ti+84+calculator+download+for+chromebook
    • https://cdn-cms.f-static.net/uploads/4494436/normal_600bbb9c98a67.pdf
    • https://static.s123-cdn-static.com/uploads/4408721/normal_5fe0a841c3d55.pdf
    • https://cdn-cms.f-static.net/uploads/4426071/normal_604d0b8a3b878.pdf
    • https://static.s123-cdn-static.com/uploads/4416659/normal_60023f11a8126.pdf
    • http://kilobowomix.22web.org/figumivi.pdf
    • https://static.s123-cdn-static.com/uploads/4385633/normal_5ff89a8fe9410.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/e239526d-9533-483f-bf4a-1e6a07faebb0/kekuwotu.pdf
    • http://vuzozan.epizy.com/enterprise_and_small_business_principles_practice_and_policy.pdf
    • https://83d7d1d1-3661-4158-a2cc-78aa4aa39d08.filesusr.com/ugd/163759_778ce714b94540539c3e7cdd48d40e62.pdf?index=true
    • http://xarinibobi.epizy.com/gakazixugamesukozadup.pdf
    • https://b1b0174c-961c-4936-87f6-765e1132391e.filesusr.com/ugd/6cf804_453cd116c8dd49238a1453cff3659ac3.pdf?index=true
    • http://folivit.epizy.com/35892125045.pdf
    • https://011f98f8-b45f-4578-a2fd-466b530f7845.filesusr.com/ugd/74e905_6bf22c0ed5244a0fb8948a2f679c07a0.pdf?index=true
    • https://53ebb62d-ddaf-432f-8dc3-1f4746653467.filesusr.com/ugd/bbd3cf_c23c268edad049f3b6497cc24af8dc47.pdf?index=true
    • https://0c7b1e5d-10e9-4c66-9a64-57e6babc74f3.filesusr.com/ugd/6b59ba_84080c89d67847c2b45c808bcd09f3de.pdf?index=true
    • https://04650017-3ca5-4b28-9d9b-11da2816551d.filesusr.com/ugd/aa03de_bf1cd36b9f804fc98ee7b42b72733d6b.pdf?index=true
    • https://c8019651-2137-4367-b38e-775fff3f8a75.filesusr.com/ugd/fc5a02_3e6942782ce34fdbab60dcc535fa9f19.pdf?index=true
    • https://3cd6846c-369c-4875-9c63-132df726a2dd.filesusr.com/ugd/7ab50f_e934d83a01584083b0b6d9b18248fab8.pdf?index=true
    • http://xoxuwev.rf.gd/35985753149.pdf
    • http://wigazimo.epizy.com/45962399853.pdf
    • http://fozosoripivo.epizy.com/cyber_hunter_apk_data_revdl.pdf
    • http://tixuveji.epizy.com/canarsie_high_school_for_medical_professions_uniform.pdf
    • https://uploads.strikinglycdn.com/files/5ad7d158-c0eb-4afb-8393-ae60b0d70035/1476969516.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ddf6.bin
85f878ddc975bd777e1e48c3c2b9f80cf30dbab8f5f00c8643c1bc78781c6052
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDF6 5608 bytes
font_01_sfnt_off0000f0fa.bin
da7a898166e0f66019f49b6791dc9c300ed8a985f8ebc66bd513c63b1f04de41
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FA 11300 bytes
font_02_sfnt_off000117ab.bin
503f5200e83b189a546b6c6e1d808633a9135186956fe76ff9bd78de3d91e3c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x117AB 16060 bytes