Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8ef9362b3710613…

MALICIOUS

PDF

75.9 KB Created: 2021-04-01 06:21:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 163a232965c4a09585743b52f9e6a67a SHA-1: 5d7abc2cfee89e8c7965c6fa9309f9a4f43ac843 SHA-256: f8ef9362b3710613ee47ff8e12c63475e4b0e84c9cb7947630bc8f37599de791
194 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, which is indicative of a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution scheme, likely initiated via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • 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://zajinet.ru/award?keyword=analytical+reasoning+book+pdf+download PDF link annotation
    • https://defupodanujazi.weebly.com/uploads/1/3/5/3/135346118/munotu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481058/normal_5febe56342e72.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471091/normal_601c7349223fe.pdfIn PDF document text
    • https://cdn.sqhk.co/wesuwajil/iiYgn8M/jowevomijumodiwera.pdfIn PDF document text
    • https://cdn.sqhk.co/xenudipu/fgiiihq/do_not_touch_sign.pdfIn PDF document text
    • https://zefugomifavo.weebly.com/uploads/1/3/6/0/136087281/e55a1.pdfIn PDF document text
    • https://kobawepa.weebly.com/uploads/1/3/1/0/131070010/2d47f33812d8.pdfIn PDF document text
    • https://cdn.sqhk.co/zokuwagopole/3daqMCy/pencil_pouch_cute.pdfIn PDF document text
    • https://kizevopizimi.weebly.com/uploads/1/3/5/3/135351298/tasixa.pdfIn PDF document text
    • https://cdn.sqhk.co/subetudagoli/gTgRThe/83863409873.pdfIn PDF document text
    • https://serijarivak.weebly.com/uploads/1/3/0/7/130776739/riwelo-leforumolamelu-lisamezo.pdfIn PDF document text
    • https://cdn.sqhk.co/xukigipeduve/dRtxjfD/nurosutiwivotijuget.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://78de399b-5cb1-4d05-8290-e7933402b20f.filesusr.com/ugd/10f998_e61512a2a4f446edbbdf9a73378a7875.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vovuzize/84410106658.pdfIn PDF document text
    • https://a8a57b57-a5e9-4b5c-b824-02731ce3a1bd.filesusr.com/ugd/cfa667_4a645165bed84c9a867fc200053fdfd8.pdf?index=trueIn PDF document text
    • https://e5447efa-8854-4d04-834e-f0bbd7438c8b.filesusr.com/ugd/ac612b_663e02d03b7f48189db67854382884c8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/dupula/33002025825.pdfIn PDF document text
    • https://s3.amazonaws.com/zupenafud/what_are_the_four_organic_macromolecules_found_in_the_body.pdfIn PDF document text
    • https://s3.amazonaws.com/pibajuwi/fukazagitoguk.pdfIn PDF document text
    • https://s3.amazonaws.com/futamo/what_is_the_best_way_to_soften_a_callus.pdfIn PDF document text
    • https://s3.amazonaws.com/pokorevalaxex/love_warrior_book_review.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e9e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E7 5708 bytes
SHA-256: c5e386dbbb954083c165f53995014dd3340a85f18aad58fe516dd0e7dd264b31
font_01_sfnt_off0000fd84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD84 10796 bytes
SHA-256: fa6c830917759a3413c49d19ecddef24e660aa57c620911e069e872e48621325