Malicious PDF — malware analysis report

Static analysis result for SHA-256 4df4c51cd358f6f7…

MALICIOUS

PDF

81.7 KB Created: 2021-04-29 18:09:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 91ca7ef25515f4a6034506f7d983dec4 SHA-1: 489037c164a21e19de3c6375c0cc07d5cd1573f5 SHA-256: 4df4c51cd358f6f7bdd8e8c3b2cccfed13f455479dd926f54a7792cffa1f08d5
124 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The document body, though heavily obfuscated, contains keywords related to device resets, which is a common lure for phishing or scamming. The presence of embedded URLs and the ML classifier's high confidence score further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9513

Heuristics 4

  • 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
  • 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://pelibifir.ru/strik?utm_term=how+to+reset+yamaha+rx-v681
    • https://joxunirefebemi.weebly.com/uploads/1/3/4/3/134319414/5616764.pdf
    • http://garant-ritual.online/36227184352rrho3.pdf
    • http://mamefumiwuto.mywebcommunity.org/judajazido.pdf
    • http://newberginvestmentproperty.com/pavefilidopegofewunoxiji6dkgf.pdf
    • https://fofosororu.weebly.com/uploads/1/3/4/6/134642422/cda0a47aca8560f.pdf
    • https://fuwefepitebu.weebly.com/uploads/1/3/4/7/134709748/76c408d.pdf
    • http://podarokinsta365.site/is_sony_a6600_better_than_a6400yfkll.pdf
    • http://xepewifub.mygamesonline.org/wififeradididones.pdf
    • http://lavka-karamel.ru/logical_riddles_with_answers_in_hindih2b8k.pdf
    • http://tixshopclub.space/one_calculator_apk_purejclwg.pdf
    • http://komozazene.getenjoyment.net/compound_shapes_area_worksheet.pdf
    • https://gosazakinuda.weebly.com/uploads/1/3/4/8/134861856/5358937.pdf
    • https://vumiluvitut.weebly.com/uploads/1/3/2/6/132696113/fagiwilavejo.pdf
    • https://faxegosesu.weebly.com/uploads/1/3/4/5/134528451/dunesip-noxadopibasoko.pdf
    • https://vudasanuvopiw.weebly.com/uploads/1/3/4/7/134737570/vopor_sewifuwovobazem_lanujukuziwop.pdf
    • http://devgm.design/how_to_get_a_water_heater_to_stop_leakingtfty5.pdf
    • http://trikotoria.ru/types_of_bird_beaks_and_feet73fj0.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/501fbffb-a869-4e30-ae99-2b91eab26a98/59104636996.pdf
    • https://uploads.strikinglycdn.com/files/7345d80c-0a98-4b5f-b2e2-0687cc93293d/bapazofowapo.pdf
    • http://lixugafepujijoj.onlinewebshop.net/isaiah_berlin_biografia.pdf
    • http://fanalejowegop.atwebpages.com/ghatna_chakra_geography_2020_in_english.pdf
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010b49.bin
1b37d0ed1265ccd0bdfb3e412142d972252fd3a9380e99770638b3c32ed3b8d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B49 5608 bytes
font_01_sfnt_off00011e5a.bin
64a95e580886271c524f616b430cfdb511151ef175366835730a3187727ba2d2
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E5A 12728 bytes