Malicious PDF — malware analysis report

Static analysis result for SHA-256 26dc258a1840ac77…

MALICIOUS

PDF

83.6 KB Created: 2021-09-12 07:38:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4a92c566ef53bf822bbd5263356bbdc5 SHA-1: 21d9271287927dc9170012c3f68abc69c295f4a7 SHA-256: 26dc258a1840ac77fd9ad71f0ef0c787f1fca214bcba7a53fb0ebba5fac72a24
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm or SEO spamming attempt. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the presence of multiple suspicious URLs suggests the document is designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://www.eatvirukai.lt/uploads/files/79605311990.pdf In PDF document text
    • http://087334211.kad.tw/kads/ckfinder/userfiles/files/1388946880.pdfIn PDF document text
    • https://888nv.ru/userfiles/file/2273144282.pdfIn PDF document text
    • http://betonkeritesek.eu/Content/files/22055473266.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/tavuwirojamuzi.pdfIn PDF document text
    • http://web5gstore.com/Files/files/welitovukinowafexaju.pdfIn PDF document text
    • http://louisamerino.com/userfiles/file/18900846951.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/97410462950.pdfIn PDF document text
    • https://redac.ch/upload/kukojerijef.pdfIn PDF document text
    • http://ptk-tent.ru/userfiles/file/ludifa.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16137fc56b42af---5853426273.pdfIn PDF document text
    • https://hurghadalife.net/userfiles/files/sositagokoniziteson.pdfIn PDF document text
    • http://lonniestireandauto.com/nbloom/fckuploads/file/lotedakegujid.pdfIn PDF document text
    • http://dautuck.com/uploads/userfiles/file/kapusovatitipivaje.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/52951433171.pdfIn PDF document text
    • https://museuminiaturesbesalu.com/files/53398902148.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/jifozerefuxubi.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f25071fcd---72109318252.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/veliweromotisaga.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/1b52a249210db03ec34e4ce6a5983354/68176006528.pdfIn PDF document text
    • https://aaaxxion.info/images/file/93349042876.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc78ac7548---55860696568.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/budepibizit.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/fubosuletubugudase.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/kazusuweganagu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=blues+basic+chordsPDF 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_off0000e286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE286 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fa98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA98 17600 bytes
SHA-256: f93935a415321e5ae2d74fd8f06d928a15e603a5b8f3c1b6ae258a160a396b35
font_02_sfnt_off00012889.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12889 10556 bytes
SHA-256: a203f52a07e74e93069ff96675298c6cc92bd32b7df4c89a6808c6f204ad159f