Malicious PDF — malware analysis report

Static analysis result for SHA-256 e2b62955aca2f63c…

MALICIOUS

PDF

78.0 KB Created: 2021-03-28 01:37:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 28944b0d960c85651afa55c8b80fdc00 SHA-1: e32838a661e2d5a7b2a31f4a9dc8c808a850648c SHA-256: e2b62955aca2f63cf5c1811ad0395a63deef3632437012c8e86b3186ed2ebec7
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many pointing to other PDF documents hosted on disposable or cloud storage services. This behavior is indicative of a link farm, likely used for SEO manipulation or to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, with the primary IOC being the initial URL that likely serves as a gateway to the link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://xezojetit.ru/award?keyword=4+week+workout+plan+to+get+ripped+pdf
    • https://static.s123-cdn-static.com/uploads/4403674/normal_5ff40639bf47d.pdf
    • https://cdn.sqhk.co/turaxulefa/icib5jg/rusomem.pdf
    • https://cdn-cms.f-static.net/uploads/4492573/normal_602a090393d5a.pdf
    • https://cdn.sqhk.co/resilano/hgidfgc/racing_in_kansas_city.pdf
    • https://cdn-cms.f-static.net/uploads/4480187/normal_6040b6b5ee0b7.pdf
    • https://cdn-cms.f-static.net/uploads/4424692/normal_6037649fef15c.pdf
    • https://cdn.sqhk.co/bepoweruga/ifghM0k/threads_pour_instagram_apk.pdf
    • https://cdn.sqhk.co/josipinu/hifggij/gladiator_rising_2_mod.pdf
    • https://cdn.sqhk.co/dapumexader/hjjfgfa/mezisitezorafe.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://18b09f4e-de4d-4c1b-9fe6-be55c63b1c00.filesusr.com/ugd/cd81e9_805588b6a55e4c9dbe6e119256adeb73.pdf?index=true
    • https://dc6b22d1-fd3c-476a-b8f1-b0505981f591.filesusr.com/ugd/ab5adf_63e4953c0a114665b1f62fe30ad4b0b2.pdf?index=true
    • https://s3.amazonaws.com/widofafane/what_is_the_role_of_public_relations_in_integrated_marketing_communications.pdf
    • https://uploads.strikinglycdn.com/files/b28de116-f4e9-4036-bd8b-a67969dda55f/30101883165.pdf
    • https://8d275f60-8e36-4e70-8574-b6d542a617c4.filesusr.com/ugd/dbf6c2_fab05c714aeb49c1ba940e9429be99fb.pdf?index=true
    • https://s3.amazonaws.com/topipovikapari/ginakaxuvuwobedekejif.pdf
    • https://86908e24-11f3-43a1-9346-bf531f45ee0b.filesusr.com/ugd/97493d_016b153a7bae41548fc628ce7946278c.pdf?index=true
    • https://s3.amazonaws.com/meludav/3858935496.pdf
    • https://s3.amazonaws.com/tobaziw/lesson_master_b_answers_algebra_2.pdf
    • https://s3.amazonaws.com/tajimipojimo/bafewufixekisiv.pdf
    • https://e05653fc-386e-4c8b-889d-738aee72c63e.filesusr.com/ugd/62421a_09df60e19bba4a6889faf85ff4ee2dea.pdf?index=true
    • https://efa91360-7c21-416c-9d60-3189e0beb381.filesusr.com/ugd/42ffc7_b3009285b9864965a2306c11f6539c70.pdf?index=true
    • https://e590c0d9-b694-44fb-9862-47327b30d8b0.filesusr.com/ugd/89363e_2f6255f06c074bbc9d760f5721a69657.pdf?index=true
    • https://uploads.strikinglycdn.com/files/9b655f43-0a36-4dd5-8fd0-0b7a3ee41c04/sat_subject_tests_math_2_practice_test.pdf
    • https://76ed6b59-b034-43ac-b949-e1c08f76e3cb.filesusr.com/ugd/ee6100_c71feb53a9544cf594d914f25b053299.pdf?index=true
    • https://uploads.strikinglycdn.com/files/887fb169-f033-4e68-87d6-3c6c63fd8b62/percy_jackson_and_the_olympians_book_2_audiobook.pdf
    • https://27a83426-c768-4525-a63d-b5b732cca755.filesusr.com/ugd/28b3f7_a986ba9401024863b8ce2691eaf36550.pdf?index=true
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f534.bin
326d59e0b17470367dab42ee267a6775409a852d686736a4f5037d7d4a9a9948
pdf-font-stream PDF embedded font (sfnt) at offset 0xF534 5180 bytes
font_01_sfnt_off00010702.bin
534ea3369b4e4021c68c5034f0cb165d74a06446132620ceb63e1657e10a4159
pdf-font-stream PDF embedded font (sfnt) at offset 0x10702 10264 bytes