Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8933daaf7465177…

MALICIOUS

PDF

84.7 KB Created: 2021-03-17 02:56:30 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 53b5806775bec8a9428d9597b3e6163e SHA-1: b50bfe424c2778b258ee27366d8ce9eaf5ca76c8 SHA-256: f8933daaf74651778079ed8a3fb69dfe461d0b7bd390510e17d6ab80345bb87f
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to direct users to malicious content. The document body, though heavily obfuscated, appears to be a lure related to 'interview questions'. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://resalured.ru/123?utm_term=tricky+interview+questions+and+answers+in+java PDF link annotation
    • http://gudelew.mywebcommunity.org/36050877676.pdfIn PDF document text
    • https://bajomunimiru.weebly.com/uploads/1/3/1/0/131070213/gofamazupop_lusebuf.pdfIn PDF document text
    • https://lebilelumebik.weebly.com/uploads/1/3/1/6/131636833/sefuraxisabab.pdfIn PDF document text
    • http://gejokakop.mygamesonline.org/18672974761.pdfIn PDF document text
    • https://laganavixafalos.weebly.com/uploads/1/3/5/3/135341912/jovitadonoxuwonexu.pdfIn PDF document text
    • https://cdn.sqhk.co/rowubuvuke/nhttVvC/64729709220.pdfIn PDF document text
    • https://tidosivapozagul.weebly.com/uploads/1/3/4/3/134390518/1003f61.pdfIn PDF document text
    • https://cdn.sqhk.co/wufevinek/jfYPOjj/fitir.pdfIn PDF document text
    • https://puzomukasudugun.weebly.com/uploads/1/3/4/8/134865935/3932883.pdfIn PDF document text
    • https://cdn.sqhk.co/wabasenenem/5Ehiiiy/earthquake_bay_area.pdfIn PDF document text
    • https://cdn.sqhk.co/noxisoture/dqAksyE/jubamufuv.pdfIn PDF document text
    • http://dosijefa.mypressonline.com/nopoxajumavojesubij.pdfIn PDF document text
    • https://pamuguvijokogag.weebly.com/uploads/1/3/4/8/134883264/9766900.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5c90cfa9-af55-48e2-9430-1f3580382729.filesusr.com/ugd/e2b09b_9d57c0bac5744434b545adf6dd2ec56c.pdf?index=trueIn PDF document text
    • https://724418e0-3ace-43c1-abd8-628b4820fc71.filesusr.com/ugd/6df952_8dcf5e0e8a5546d69e15927b5e4a0973.pdf?index=trueIn PDF document text
    • https://cd753cf5-d90a-4073-9c55-931a76e81761.filesusr.com/ugd/8826df_2e87e0d9d1d54f15b95d3ebc87fc8110.pdf?index=trueIn PDF document text
    • https://ebc1add8-0b9d-418e-9e4a-1e287827e933.filesusr.com/ugd/ab63e3_01ec1e1e537e45e0aefbd68554f9451c.pdf?index=trueIn PDF document text
    • https://1e35b969-1f99-48dc-8aa8-d0fb9638bdc8.filesusr.com/ugd/970baa_f411bddb1a2542268c4f53e57b92d5c5.pdf?index=trueIn PDF document text
    • https://006b50d4-ad2a-4261-8279-34542eb0d7b0.filesusr.com/ugd/a640e9_912b978859ad472fa8fa05909fcd9771.pdf?index=trueIn PDF document text
    • https://081e7fb2-604d-424b-9b75-a58d54a71a44.filesusr.com/ugd/abd6ea_f3213b6d99ae4191bb6103c1b4b9db51.pdf?index=trueIn PDF document text
    • https://ebed6276-6372-4ddf-adad-9a0fa504b99f.filesusr.com/ugd/805d2a_bf56fc3675634382a877ee00ecb8f330.pdf?index=trueIn PDF document text
    • https://5e024257-ca51-40df-b6b5-a3104c7b7124.filesusr.com/ugd/97368a_a51a2ae117b740e0966b6e79f47f204f.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_off00010fb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB7 5368 bytes
SHA-256: 7dfbb6446a43efd5c3be0d5c5bfe8f33d691af6df55815a15e574f9a2971c266
font_01_sfnt_off0001222a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222A 10592 bytes
SHA-256: cdd67107a8bb32a5017df356e61efdad9218948c31b8e296390d7de654b68f30