Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf5ff36235648437…

MALICIOUS

PDF

86.6 KB Created: 2021-09-06 11:48:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 42fc2e673af43650020e2fa073170c68 SHA-1: b12b84f2bdcb9edf7bc1d7ffa27e2a6f757114c3 SHA-256: bf5ff36235648437724711aee3736e9d7303054c9df836f1d39d60b6df806b4c
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Several URLs point to potentially compromised CMS uploads or disposable hosting, suggesting an attempt to manipulate search engine results or direct users to malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically highlights the nature of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • 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://mamitobe.ru/files/file/newukipolivozopa.pdf In PDF document text
    • http://dexgerm.com/data/file/userfiles/files/vowigibujapav.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/42989717775.pdfIn PDF document text
    • http://moestuinwebshop.nl/userfiles/file/10539471724.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/75704504880.pdfIn PDF document text
    • http://sequirk.ie/userfiles/file/76749963887.pdfIn PDF document text
    • http://velocimapper.com//webfiles/file/lepasixotixat.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/puwukogebozodaniwi.pdfIn PDF document text
    • http://gymostrov.org/gymostrov/userfiles/file/fidowutokasixokipotixubo.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/040a8a965936f7267f65623614b71bc4/sufubatofe.pdfIn PDF document text
    • https://sakura-bashi.com/uploads/files/202108310247286995.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/maxojagikux.pdfIn PDF document text
    • http://dunajecbiala.pl/upload/File/bilepusupepej.pdfIn PDF document text
    • http://ngnjl.com/userfiles/files/vikivote.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16128af4d02741---rusumosapujagunolome.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/8895c33fadf0a8001037be9776122756/61389340479.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083f13fc0aa4---xozigipivezi.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/78562542468.pdfIn PDF document text
    • http://idroter.org/userfiles/files/70318971364.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c96d4160f8---12901819028.pdfIn PDF document text
    • http://agilesolutions.in/uploads/94161890032.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1bc6a6d70---63764233736.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6b90804a63---debejukebutivifa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=photoshop+7+all+shortcut+keys+pdfPDF 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_off0000e854.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE854 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010066.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10066 18864 bytes
SHA-256: 3eef63102af5e45792db9c4ff162191ab747b70a4737696af39308a5b9a911e7
font_02_sfnt_off000132cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132CB 10876 bytes
SHA-256: e58e4cb768a8fee0d0a3559732df2298cbedc1db645e418c58534adb168b1d21

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