Malicious PDF — malware analysis report

Static analysis result for SHA-256 830cb688fc91eae1…

MALICIOUS

PDF

82.6 KB Created: 2021-04-24 00:04:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 91d24e5fefd8aa8cacd05cdf0e95352e SHA-1: 7818c2fc7366155258f95f13bd37a563cc5533ee SHA-256: 830cb688fc91eae14942df885dafbddcb7a8201d8cc351f293dce6a185d55c8b
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains an external URI pointing to 'zajinet.ru', which is likely part of a phishing or malware distribution scheme. The PDF's structure and embedded content suggest it's designed to trick users into visiting this malicious link.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://zajinet.ru/strik?utm_term=snark+guitar+tuner+battery+type PDF link annotation
    • https://cdn.sqhk.co/gadewekunel/ecihjay/download_horde_defense_mod_apk_terbaru.pdfIn PDF document text
    • http://bigpleasure.ru/singer_quick_fix_sewing_machine_manualvooix.pdfIn PDF document text
    • http://songkfrk.site/geronimo_stilton_books_age_groupiw7o5.pdfIn PDF document text
    • http://domen3.club/what_is_suffix_ly_mean7h9pm.pdfIn PDF document text
    • https://cdn.sqhk.co/mivadunoxo/BIj2ihm/42460533154.pdfIn PDF document text
    • http://rubka.space/taps_to_riches_money_hack_apk6y4hu.pdfIn PDF document text
    • http://befotuke.mywebcommunity.org/dd_online_virtual_tabletop.pdfIn PDF document text
    • http://dexaputanit.mygamesonline.org/dorothy_roberts_killing_the_black_body.pdfIn PDF document text
    • http://nujagexurej.medianewsonline.com/how_to_install_leg_pulley_on_total_gym.pdfIn PDF document text
    • https://cdn.sqhk.co/jivomawufem/hgngdig/thimbleweed_park_switch_physical_ebay.pdfIn PDF document text
    • http://leninuludobodu.mygamesonline.org/ayatul_kursi_complete.pdfIn PDF document text
    • https://cdn.sqhk.co/molodomo/dlr3gVa/xivura.pdfIn PDF document text
    • http://albatros-trans.ru/fruits_and_vegetables_having_vitamin_dwbhm3.pdfIn PDF document text
    • https://cdn.sqhk.co/wibepudib/iSjiyih/lagu_ashilla_zee_bieb.pdfIn PDF document text
    • http://vazawujuzu.sportsontheweb.net/honda_eu2000i_carburetor_bowl_gasket.pdfIn PDF document text
    • http://wapadax.scienceontheweb.net/saving_zoe_alyson_noel.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/567330b8-7924-489c-bcf7-96a0cde62a81/16857862167.pdfIn PDF document text
    • https://s3.amazonaws.com/povelenavuviw/chrome_untuk_kali_linux.pdfIn PDF document text
    • https://s3.amazonaws.com/nuxomigo/gikawanuxuzesisa.pdfIn PDF document text
    • http://livirava.atwebpages.com/tagosipikubemuxovon.pdfIn PDF document text
    • https://s3.amazonaws.com/nonipesikiri/gaunts_ghosts_audiobook_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c3b50ed6-a8d9-4534-9fbb-3ac111f75b7a/troy_bilt_tb130_review.pdfIn PDF document text
    • https://s3.amazonaws.com/xowasosuf/how_to_adjust_sights_on_taurus_g2c.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9ea2cf5-2e5b-4c42-8cd1-0bb6544118b7/jagalukezozasadufojegur.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/155f2135-c759-4b73-b5a6-fbeda8674e54/sistema_endocrino_del_cuerpo_humano_para_nios.pdfIn PDF document text
    • https://s3.amazonaws.com/jinabom/cinder_book_summary_sparknotes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b24bbc51-4df7-4ebd-8a60-1727d25542c8/marlin_model_60ss_review.pdfIn 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
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eedb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDB 5184 bytes
SHA-256: 899b944ecceb679fc5fe3a1bb629afde894ca7ef9081c578f99a73e66a7a640e
font_01_sfnt_off00010098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10098 11356 bytes
SHA-256: 2002e537051941a17e684d4ea4d4c1421c6b9c7e76ce7491f71988a8a4b71922
font_02_sfnt_off0001276d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1276D 16120 bytes
SHA-256: 2cfc97915d250804213c9b0e6ad261e0979cd38371fb36ec9174dea58a153a3e