Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b843c92faeeaa57…

MALICIOUS

PDF

88.9 KB Created: 2021-03-02 06:39:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: c8dda05d1339e6b22c8c628c0986011c SHA-1: bccca4d8a6af04ebaedd0dada86e9ee95862a305 SHA-256: 1b843c92faeeaa578ed8e396181913dfaa9e9cd82850b4dc8570e4cf0466b11f
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm designed to direct users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links. The document body itself is largely unreadable due to encoding issues but contains metadata suggesting it was generated by wkhtmltopdf.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • 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 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.
  • 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://kuzutuzo.ru/strik?utm_term=how+to+thank+someone+for+a+prompt+response PDF link annotation
    • https://cdn.sqhk.co/wedegetuso/iaG32if/zoxafipobuwezegewume.pdfIn PDF document text
    • https://cdn.sqhk.co/bikegola/SjaQx7C/galaxy_bug_space_shooter_hack_mod.pdfIn PDF document text
    • https://mekumago.weebly.com/uploads/1/3/5/9/135981587/5304279.pdfIn PDF document text
    • http://zesamoa.online/walter_chilambo_songs6s35v.pdfIn PDF document text
    • http://vojemodipu.sportsontheweb.net/62259859205.pdfIn PDF document text
    • https://cdn.sqhk.co/dojerilu/hjigiji/45078779410.pdfIn PDF document text
    • https://regurawuxafedan.weebly.com/uploads/1/3/0/7/130740517/3928795.pdfIn PDF document text
    • http://subbellassecret.com/vitamix_e320_explorian_blender_accessoriesngxqm.pdfIn PDF document text
    • https://bupulaserora.weebly.com/uploads/1/3/1/4/131437689/pobewebov.pdfIn PDF document text
    • https://cdn.sqhk.co/tuxonewebuke/2Sgf69C/90893118950.pdfIn PDF document text
    • http://mapotilij.mygamesonline.org/nojutulegase.pdfIn PDF document text
    • http://usacreditcheck.info/word_games_for_9th_gradersdnslk.pdfIn PDF document text
    • https://cdn.sqhk.co/vexorikodo/fpAipjh/gepapifurupo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://kunibenurupamiv.rf.gd/sejurivenuseragijuw.pdfIn PDF document text
    • http://liroporuki.myartsonline.com/marlin_336_sc_35_rem_value.pdfIn PDF document text
    • http://bowegasobufur.myartsonline.com/2019_harley_davidson_service_manual.pdfIn PDF document text
    • http://kofaxafogi.myartsonline.com/map_of_the_world_with_country_names_and_capitals.pdfIn PDF document text
    • http://xovanesoku.epizy.com/85543936166.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e047.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE047 8956 bytes
SHA-256: d507d544671bde135ecf2e4c291afbb1a193bef32633451e28ee502d2604f59a
font_01_sfnt_off0000fe9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9E 5224 bytes
SHA-256: 050f7057d3973e4b5b47287afbfda7a06473b3ff9035315459b2967712e4bf08
font_02_sfnt_off00011042.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11042 2944 bytes
SHA-256: c452ffe4ac368949a52d8ae13bbf28a82440802df70936981f0b1db29a734ebf
font_03_sfnt_off00011a4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A4A 10976 bytes
SHA-256: d271e261084cfeb0bdcbfdbd626d2160a900c124af35552221f3a8ae3e2649f3
font_04_sfnt_off00013fcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FCC 16076 bytes
SHA-256: 1572f1bef06e94643c552f70f3ef07ecee9bf7de88dacbdbabe2fa1db5c51cc3