Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd6851c2857b6a1f…

MALICIOUS

PDF

74.8 KB Created: 2021-06-20 13:16:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: e1107f2e7b71e2175e88eef7cb4b2179 SHA-1: c6b5ac4bbaaa756ae868cac18c650b89f8439a9c SHA-256: bd6851c2857b6a1fe94ec7b7b8791bd6c58d98955151fddfef161a6938d9d2cb
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 0.9998

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://signexpowholesale.com/project-new/christianbook/upload_images/file/dufikiredi.pdf In PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a556cbad978---40121552516.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/7870105612.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/59853856299.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/7e524e2ebdfd305d8d74392bc69fae07/41688600761.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a04816c8c10---duros.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089a9af9d916---lixavatuvobet.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/ea77b80fc1c029109266614bdb5b09b4/71027609966.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b325e79c11a98771f4fb3cf7923c968b/74388514054.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/7bc926ff814ed28c29a36391aad544d3/79596446577.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a366b81d9e7---94763624044.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/tsheresio72mqs3nnqp4h2jjet/kosin.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/95839412042.pdfIn PDF document text
    • http://novussiteyonetimi.com/uploads/file/tibulufojifekinumadu.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16084b6d7db573---pogobebujumeroxegopexakap.pdfIn PDF document text
    • https://starbox.fr/img/files/jejowisu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=mia+khalifa+new+xxxxPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB1 4408 bytes
SHA-256: 826bd560cfebf231e297155b7b1212fa96e0abb3c76bbb7d64336dfece77449a
font_01_sfnt_off0000e9a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A1 10944 bytes
SHA-256: 0ed46bed040273cb02ff6b7122b457a3741ddc950143c431d9dd3cf2fd9d7622
font_02_sfnt_off00010f05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F05 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333