Malicious PDF — malware analysis report

Static analysis result for SHA-256 ed37f4d8cddf471d…

MALICIOUS

PDF

90.8 KB Created: 2021-06-14 06:34:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 91bc0f95e97a3042bfa511d068ef5021 SHA-1: 9ba31cde80811db73399354207dfb8466a885d7c SHA-256: ed37f4d8cddf471d618bbece210ce39cd26c01ed74ae2212b5655aa1a507d8dc
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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 https://queure.ru/uplcv?utm_term=brs+kash+throat+baby+free+mp3+download PDF link annotation
    • http://szyldkj.com/luodan/images/userfiles/file/segox.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/571849d36d1b03a8c4cd769c5206c1b5/66926088334.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/rakawewikexuko.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abdc034e710---birutovajines.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609300cf9af8e---zinuxejagudavege.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160818bc26b261---givufijetegupuxek.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c19a24e07d0---25351925830.pdfIn PDF document text
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/02699bde0e9514accbbe68f0b3638561/19468872558.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160c5eaac65c43---77123890478.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/ctmmsfph63k2on0gij2459vc44/dapar.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b392350ca01---36825813161.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb99e96bb0---sarikito.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b941e5481d9---rularojixakajezulanetetuw.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd05ad60c1---52584884245.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/fudeweze.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160a0226916907---bimilakaletaguxavamuw.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/d1d6305180b90333a07b3959c1e6aa0a/tulevugitiwik.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ebad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBAD 6744 bytes
SHA-256: 048fb1891f432488516cd811e7b04d68e7d39e548ca3495625137f8fb0c23ff4
font_01_sfnt_off0000fc92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC92 5892 bytes
SHA-256: 20795100f72a8bf76e29201b9174327d27cd401c972e53f204ac50890edc2fd9
font_02_sfnt_off00011081.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11081 3008 bytes
SHA-256: 8d97f74d604cdcd08019910cd582ec49a8ee5c581d17f7595a01f49b98bc35af
font_03_sfnt_off00011d16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D16 12444 bytes
SHA-256: 96eb341cdc51de3382bc2cec80acd15ea324dda43d8a96762a9b65b350f9f0e9
font_04_sfnt_off000147ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147AB 16148 bytes
SHA-256: 64f21e55c2f29c6f605e8f9fd96e7f7b34f9b4a26fdc717ddead948457370e3b