Malicious PDF — malware analysis report

Static analysis result for SHA-256 83aaffb30b5b932d…

MALICIOUS

PDF

77.6 KB Created: 2021-09-13 07:27:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f478ad469449d4975903b34f75daccf9 SHA-1: a77086cce49235d9808a3af3435525cabaa249e4 SHA-256: 83aaffb30b5b932d84a1965b08285829de0c34ef3e1fc538b1a7060213313d44
74 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, indicated by the PDF_JS heuristic, which is a common technique for executing malicious code within documents. The ML classifier strongly flagged this PDF as malicious. The sample also exhibits characteristics of a link farm, with numerous external URIs pointing to various domains, likely intended to obscure the final malicious destination or spread the malicious activity across multiple sites. The embedded JavaScript likely facilitates the redirection to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://i-p-p-c.com/ckfinder/userfiles/files/muveruvugukuzafisumin.pdf In PDF document text
    • https://dpengineerindia.com/admin/userfiles/file/69089486947.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/tilegivexorirara.pdfIn PDF document text
    • https://stehovani-ostrava.cz/static_pages_files/file/15135996604.pdfIn PDF document text
    • https://gencerenerji.com/resimler/files/petalajozegunat.pdfIn PDF document text
    • http://chenruichem.com/upload/files/28840863230.pdfIn PDF document text
    • http://dallapietamarchisio.it/userfiles/files/mukafafikunegataxarara.pdfIn PDF document text
    • http://xn--80aamwn.xn--p1ai/userfiles/file/56677420958.pdfIn PDF document text
    • http://cauthangdep24h.com/upload/files/32246425535.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/15203776234.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/xidab.pdfIn PDF document text
    • http://christopherdallo.com/file/kubamebameb.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/99424441315.pdfIn PDF document text
    • http://mrcookie.tw/upload/editor/file/091444436687.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/87127d5954d72ea11d17ba28d0e265a4/91886984709.pdfIn PDF document text
    • http://leebyenghun.com/new/upload/board/files/zejatonobugamefub.pdfIn PDF document text
    • https://businesslife.com/content/files/74710775023.pdfIn PDF document text
    • http://professional-tuner.at/uploaded/file/48397197013.pdfIn PDF document text
    • http://tomei4x4.jp/js/upload/files/22340123492.pdfIn PDF document text
    • http://tfforming.ru/d/files/75673649338.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/5ps66dh1at4hil8gm4kkneo0vv/fubaxigebizapefojase.pdfIn PDF document text
    • http://eksternest.be/images/file/fejatulefawixodipifi.pdfIn PDF document text
    • http://esen-life.com/userfiles/file/xabekik.pdfIn PDF document text
    • http://ayhancevik.com/images_upload/files/53194051331.pdfIn PDF document text
    • http://baoveantam.info/upload/files/lavox.pdfIn PDF document text
    • http://ebbers-schilderwerken.nl/uploads/files/rogimenotobafolobajuvi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=fundic+part+of+stomachPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000caee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAEE 17264 bytes
SHA-256: c95db3a95e71be9ca167ff6da8e554740a4331052db6562b39f585f66f8ab0a0
font_01_sfnt_off0000f807.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF807 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001101e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1101E 10784 bytes
SHA-256: d0c94b1d4b7baca60a46edf012f69a0aea5385efb902bb58947d33b17cf28265