Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c1589d318f6f1b4…

MALICIOUS

PDF

88.1 KB Created: 2021-03-15 01:33:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 795877c7f1537c13dbee87b15c18ba6d SHA-1: 8e1fcd816b64c399be229c5e6d2cbfd31970af4d SHA-256: 6c1589d318f6f1b4b50ee4967dd64ae880873036644f284b3411f23d7831c179
186 Risk Score

Malware Insights

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

The PDF document contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate this behavior, and the ClamAV detection further supports its malicious nature. The document body, though heavily obfuscated, appears to reference 'Airsep oxygen concentrator service manual', likely a lure to entice clicks on the embedded malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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/wix?keyword=airsep+oxygen+concentrator+service+manual PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4454559/normal_60198eec65970.pdfIn PDF document text
    • https://cdn.sqhk.co/tijinujul/FghjiQM/37386634981.pdfIn PDF document text
    • https://cdn.sqhk.co/mozoposowi/iuigZHQ/boo_app_without_watermark_download.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4474992/normal_5fca4af31a02c.pdfIn PDF document text
    • https://cdn.sqhk.co/xaleteser/seeVjdH/gidajipinanusiwexo.pdfIn PDF document text
    • https://cdn.sqhk.co/vefapatape/hfYjhgj/banner_umc_payment.pdfIn PDF document text
    • https://cdn.sqhk.co/zifiguwosu/jdggygi/crazy_cooking_chef_kitchen_fever_food_games_apk.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461773/normal_6046cc93c8573.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459467/normal_600a21a3b3073.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/nakevoja/musikule.pdfIn PDF document text
    • https://7aff118d-26f6-4d76-9bc9-1838009e7274.filesusr.com/ugd/f80014_b162f8e9b3bc489da40e55f1f56e2d01.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/dedinavesute/guided_reading_activity_11-_2_world_history.pdfIn PDF document text
    • https://d25e5d79-f3dc-43ab-8538-58f2f4730235.filesusr.com/ugd/898300_110dbdf78a284b12be5b7f4dda127323.pdf?index=trueIn PDF document text
    • https://5fb42ee6-a9be-400a-98f2-f9d4b9f720c8.filesusr.com/ugd/1813b3_1c22e7221cee4588a07817bf3f6b4146.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fupanabivote/81626057471.pdfIn PDF document text
    • https://s3.amazonaws.com/rimejiguvif/vebatugexokaxizuxi.pdfIn PDF document text
    • https://2cc12256-1025-444a-bacb-901a9f007bda.filesusr.com/ugd/d1fcfc_b8f36b3216ff432793e165bb5b226c5d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bipovoromoj/javukevazaz.pdfIn PDF document text
    • https://d670dda7-df53-4ef1-8eda-d3256df28744.filesusr.com/ugd/dbbbec_a63406b153b649cfb6a6fe77c9537e48.pdf?index=trueIn PDF document text
    • https://459fb65c-52af-4c88-885a-43a44fbeaf25.filesusr.com/ugd/6a7407_91ebe50a24be4078aa4ab5725344538f.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/somamere/lesonu.pdfIn PDF document text
    • https://s3.amazonaws.com/nitatotol/86608631524.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_off00010ec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EC5 1872 bytes
SHA-256: b1b733d6dcd41c651d24b99c9f5200ade4dd71601f7ee8dbd3095764b9703bfb
font_01_sfnt_off000117ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117BA 5472 bytes
SHA-256: cae5fc6835a8b67fd85a6d77183f45537beca1e16512f6368bc931916672c138
font_02_sfnt_off00012a59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A59 11276 bytes
SHA-256: 8adf61236a305f34cb347bb29e2327b21dd9646ebf180f340d3a228423c76337