Malicious PDF — malware analysis report

Static analysis result for SHA-256 3875bf201da60978…

MALICIOUS

PDF

96.1 KB Created: 2021-04-24 07:15:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: c80a16393f3e8890f88faf8b45393d55 SHA-1: 9b8ed038baf96a32170698fb4b6469af91ba62f7 SHA-256: 3875bf201da60978db631140469109deae97b937ea32b610ab1a62bbf14d2371
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample is a PDF document that contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO poisoning attempt. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document's content is designed to trick users into installing software, a common social engineering tactic. While no scripts were directly extracted, the PDF structure and link farm behavior are indicative of malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://seumenha.ru/strik?utm_term=grammar+correction+english+free PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4480423/normal_6059d224dc49c.pdfIn PDF document text
    • https://notilapixoto.weebly.com/uploads/1/3/4/3/134397855/nelikekovamiz.pdfIn PDF document text
    • http://tijudozi.scienceontheweb.net/rorewuten.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492253/normal_603f157e931d4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411500/normal_60464ce92f18f.pdfIn PDF document text
    • https://cdn.sqhk.co/ramejolir/sNMsoii/sufisefarobenuluxilemikam.pdfIn PDF document text
    • https://cdn.sqhk.co/safubuguva/Ljixvja/54135319459.pdfIn PDF document text
    • http://fazurusitu.getenjoyment.net/65968509616.pdfIn PDF document text
    • https://cdn.sqhk.co/fusajovogi/qUtjdhb/ketegodeterunu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369162/normal_5fe9b8dfc529e.pdfIn PDF document text
    • https://cdn.sqhk.co/rolekixawute/igO8kDf/98819206057.pdfIn PDF document text
    • https://nitiruminaxodax.weebly.com/uploads/1/3/0/7/130738633/3376599.pdfIn PDF document text
    • http://moxipafuxoxo.mygamesonline.org/16327234507.pdfIn PDF document text
    • https://cdn.sqhk.co/visukodo/WljdRvd/roman_reigns_wwe_champion.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387031/normal_601f114397265.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bojefej.epizy.com/jaxuted.pdfIn PDF document text
    • http://rexivire.epizy.com/wande_coal_bumper_to_bumper_video.pdfIn PDF document text
    • http://vesuduw.epizy.com/80872034237.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/68623485-34d0-4adc-978d-a661859fba80/childrens_islamic_story_books_online.pdfIn PDF document text
    • http://xibunagevidaze.rf.gd/life_is_never_perfect_quotes.pdfIn PDF document text
    • http://woniladorunuf.epizy.com/garugubokodazobimejilob.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/caa85ce6-d0f9-40a7-b72f-c31f3310f7ce/addictive_drums_2_full_free_download.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013af1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AF1 5324 bytes
SHA-256: 0fe7b5bf65e98bfed828f33bcce32fe31a7b11b14a282166ca4ff92dd928062d
font_01_sfnt_off00014ce4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CE4 11384 bytes
SHA-256: c16d8fd71e6a5729709d0a86466aab545150546cca62c009871e33a769e4338c