Malicious PDF — malware analysis report

Static analysis result for SHA-256 7ca4acd6d3afd6a9…

MALICIOUS

PDF

84.4 KB Created: 2021-04-22 19:15:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c3f47ae921e892134946e2084cab5729 SHA-1: 2941b4fced32f2c32efc99dfe90ccedb404e508f SHA-256: 7ca4acd6d3afd6a9461bbef308cbee07a847ead5a3eba10c3e8850a4eeb95b0e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many of which are dynamically generated, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were directly extracted, the PDF structure and numerous external URLs point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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
  • 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://dafemum.ru/strik?utm_term=what+effect+did+boiling+have+on+enzyme+activity+of+salivary+amylase
    • https://cdn.sqhk.co/jimikafede/djfjgav/video_editor_and_video_maker_apk_mod.pdf
    • http://faceskinagainbeauty.xyz/30783451881asbx9.pdf
    • http://mailedflkf.site/c_programming_language_handwritten_notes7ja5x.pdf
    • http://best-store.club/nwt_bible_pro_apkjr2q6.pdf
    • https://cdn.sqhk.co/definuseju/Hgfyjfv/within_movie_2009.pdf
    • https://sofirutowik.weebly.com/uploads/1/3/1/3/131381411/pufuwelutuzu.pdf
    • https://cdn.sqhk.co/budatumibowu/b2Wi2N0/milekezisevo.pdf
    • https://cdn.sqhk.co/jefadata/hWjiBhi/fmla_guidelines_new_york.pdf
    • https://biziliwedurukax.weebly.com/uploads/1/3/4/8/134889104/sejedadu.pdf
    • https://cdn.sqhk.co/bexoninodag/hzRgjTS/wojezakerutenakusajudizit.pdf
    • http://reduslimitaly-ufficiale.site/subway_nutrition_protein_bowlyuop4.pdf
    • https://jawuvufos.weebly.com/uploads/1/3/4/8/134856807/e6fbfc.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/99514ae6-d47e-419b-8147-4bc5ae961371/how_to_align_hp_officejet_pro_8600_online.pdf
    • https://1b53f64c-3596-40ff-86ea-95cec8902569.filesusr.com/ugd/838e7e_59498fd94c1b4519a3b06a5121b7e0af.pdf?index=true
    • https://uploads.strikinglycdn.com/files/435ae06e-b3c2-4cd9-9326-12b5420fde47/realtek_high_definition_audio_driver_windows_10_lenovo_ideapad_110.pdf
    • https://6acbaf94-bc62-4fdb-9a00-914544f0b606.filesusr.com/ugd/3ee118_b33e8ebac0094f8484268ef1da953cf7.pdf?index=true
    • https://uploads.strikinglycdn.com/files/bf7ced07-9895-4c85-a51b-c44e9a1ae857/76059547744.pdf
    • https://uploads.strikinglycdn.com/files/7e25d30c-4aac-4f6b-b36a-4c82b09ea448/a_lie_too_big_to_fail_book_review.pdf
    • https://uploads.strikinglycdn.com/files/f3314667-98d5-4e31-82bb-5f3582bc959a/muvixesaxipozezadek.pdf
    • https://uploads.strikinglycdn.com/files/b0e4e5cb-ca8d-45ee-84ec-d93a3a867f95/poker_rules_2_pair_tie.pdf
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fc8c.bin
9c84aca5171cf4522e1fd23f3e5391e17c8e645cdcb740b4c3036af6865bd014
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC8C 2900 bytes
font_01_sfnt_off000106d1.bin
356c83013e4373c89641ad33ffe2749f9d9b9551fea294ec257c17addff1993d
pdf-font-stream PDF embedded font (sfnt) at offset 0x106D1 5800 bytes
font_02_sfnt_off00011a85.bin
114e6ce12a4d41efb11f7d9b7f704cfbbc3cd0aa96c42b1ce1f0fd8177d9fc1f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A85 11712 bytes