Malicious PDF — malware analysis report

Static analysis result for SHA-256 27bec4e443799db5…

MALICIOUS

PDF

86.5 KB Created: 2021-04-04 17:33:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e304730dd5d539b95333f65f7c43d86f SHA-1: 7590065dcac6ace3f6931d9534ccbc1e3adf4bbb SHA-256: 27bec4e443799db52cf80f915bd33fd99d72f39502fbb8c534b7b4251f709deb
164 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with critical heuristics indicating a PDF link farm. The embedded URLs, particularly 'https://nipisod.ru/strik?utm_term=grammar+land+worksheets+pdf', suggest a phishing or SEO manipulation attempt. While no scripts were extracted, the PDF structure and numerous external links point towards a malicious workflow designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nipisod.ru/strik?utm_term=grammar+land+worksheets+pdf
    • https://fenikazegalo.weebly.com/uploads/1/3/1/3/131379965/jogakef-xesitexazap-wowuwikavejef.pdf
    • https://fugogifozu.weebly.com/uploads/1/3/4/8/134888696/b74c2.pdf
    • http://gakukuketisalum.scienceontheweb.net/l_almanach_de_la_sorcire.pdf
    • http://ostanni.fun/zeborinifovoycb8.pdf
    • https://komuwewolidixat.weebly.com/uploads/1/3/4/8/134871085/b4d71dff2e4183.pdf
    • https://lamalirigade.weebly.com/uploads/1/3/4/5/134595912/fudigiriwu.pdf
    • https://wajifisawebe.weebly.com/uploads/1/3/4/4/134480175/bdc1e75cf419b.pdf
    • http://trells.space/99369648213sp1oj.pdf
    • http://migriruy.ru/talewagofoxeguligffgt2.pdf
    • http://gsmall.space/27194722935xhscw.pdf
    • http://voztrans.ru/rorunut9aq.pdf
    • http://setopin.mypressonline.com/burger_king_dollar_menu_2021.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/5c2c3355-4661-433d-bc83-9ae9e53ae62b/28026221104.pdf
    • https://uploads.strikinglycdn.com/files/4290a865-07aa-4bdf-808a-113f6d2f01fa/joking_hazard_how_many_players.pdf
    • https://uploads.strikinglycdn.com/files/143d7f26-c75c-46c2-9939-70a14d1ecf53/58282151217.pdf
    • https://uploads.strikinglycdn.com/files/59bdc3dd-e3b0-4bf7-8e68-a735f8ae3d55/8041784108.pdf
    • https://uploads.strikinglycdn.com/files/cb6a42a6-52c6-48fd-b4a4-9b26b5c2409f/what_is_the_poissons_ratio.pdf
    • https://uploads.strikinglycdn.com/files/8c404fd0-7aa9-4f23-92ce-f328a34f205a/dell_790_sff_weight.pdf
    • https://uploads.strikinglycdn.com/files/880e725d-fcea-46aa-8fcd-0fee059e052d/one_minute_mysteries_download.pdf
    • https://uploads.strikinglycdn.com/files/c4d26743-23f1-4bf8-b587-ac8b4811ae68/30358764781.pdf
    • https://uploads.strikinglycdn.com/files/d49268b2-7855-4e34-8947-642cec207e80/hope_in_the_dark_rebecca_solnit_quotes.pdf
    • https://uploads.strikinglycdn.com/files/b1b72983-eefa-4037-b268-4c92fa2a8d1a/1984_george_orwell_study_guide_questions_and_answers.pdf
    • https://uploads.strikinglycdn.com/files/23ad1679-53f7-4aca-9b41-948d7cf611c8/wilderness_survival_kit_for_sale.pdf
    • https://uploads.strikinglycdn.com/files/724a0a2e-be5e-4bef-a214-b0658c856d6a/zizigas.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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f61d.bin
73f7883e5d072d0dbe6ce624b71318c8ce3ffeb346c9a4667de699ccfd17d99d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF61D 5468 bytes
font_01_sfnt_off00010898.bin
6d2a3a16cc464ce72cf05976c7f96a31c93af2202e0dc760c37a694345e222ee
pdf-font-stream PDF embedded font (sfnt) at offset 0x10898 1800 bytes
font_02_sfnt_off00011128.bin
45c2f802ec1660c8f9c15c9604b640634b4a7086fa894dcd6de6857fe0f562dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x11128 10724 bytes
font_03_sfnt_off000135c8.bin
b2563e85233037e3c2780690ed1455257f868516b5a962e54e6ffe29314c9cb1
pdf-font-stream PDF embedded font (sfnt) at offset 0x135C8 16312 bytes