Malicious PDF — malware analysis report

Static analysis result for SHA-256 9dc23b9a55d57d80…

MALICIOUS

PDF

73.6 KB Created: 2021-04-12 08:24:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3e13825d9905a7376e420846f1e23cec SHA-1: d00b3fa38007209ecd01eb630b5e3548e31d276f SHA-256: 9dc23b9a55d57d80589a51786e60e367d02f3c7861ec3c56baf9b94bc1f68ec4
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various PDF documents. One of these links, https://fokemale.ru/strik?utm_term=box+and+whisker+plot+worksheets+high+school, is directly embedded in the document's URI. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution, despite the lack of executable scripts. The file's structure and embedded links suggest it's part of a link farm or SEO abuse campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • 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
  • 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://fokemale.ru/strik?utm_term=box+and+whisker+plot+worksheets+high+school
    • https://static.s123-cdn-static.com/uploads/4454973/normal_5ffd060543812.pdf
    • https://cdn-cms.f-static.net/uploads/4505125/normal_5fd9d5f747655.pdf
    • https://static.s123-cdn-static.com/uploads/4463275/normal_5fcc7d49468d4.pdf
    • https://cdn.sqhk.co/bobudozoke/z2yjbWl/rotbuche_blattform_blattrand.pdf
    • https://cdn-cms.f-static.net/uploads/4487625/normal_6028928fba23b.pdf
    • https://cdn-cms.f-static.net/uploads/4403421/normal_5fdbec4698b21.pdf
    • https://cdn-cms.f-static.net/uploads/4387921/normal_6049377e38343.pdf
    • https://cdn.sqhk.co/ramejolir/jjiqhgH/64715404308.pdf
    • http://m-laskin.ru/sepuriragemelominijulaziptt9kz.pdf
    • https://cdn.sqhk.co/zimuteraf/4WDjhii/a_bread_factory_movie_streaming.pdf
    • https://cdn-cms.f-static.net/uploads/4470385/normal_601e1be0ad997.pdf
    • http://yesstore.pro/we_wish_you_a_merry_christmas_piano_tutorial_sheet_music_bossocp7e.pdf
    • https://cdn.sqhk.co/nelufebo/XiiEWjc/dapatosedesuxak.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/rijaliwiguvex/chromaticity_diagram_template.pdf
    • https://s3.amazonaws.com/guxosa/i_am_still_angry_quotes.pdf
    • https://f38be386-5799-403b-9303-fb121113655a.filesusr.com/ugd/6f1aa7_2c19abedacaa4bb3ad74565463b17aaf.pdf?index=true
    • https://b4140449-9b96-4148-8619-c9b3eed7b48c.filesusr.com/ugd/c33cdb_47829b7f0baf4fc1a2e2dc7c120374b9.pdf?index=true
    • https://s3.amazonaws.com/naxozelozude/nanuzaxavadebo.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e41c.bin
a6060ed18f02b9ce594bad933f148091404f72fd1f44ba5332b75728a4cf4234		 pdf-font-stream PDF embedded font (sfnt) at offset 0xE41C 5608 bytes
font_01_sfnt_off0000f74d.bin
fc705ec23a6c9480b10ea83f36c3a7a27b479fd45a228536d7b92c8b221a250f		 pdf-font-stream PDF embedded font (sfnt) at offset 0xF74D 9976 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.