Malicious PDF — malware analysis report

Static analysis result for SHA-256 2bcb04dd74fc3d0d…

MALICIOUS

PDF

86.1 KB Created: 2021-05-21 17:57:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2162b60dec8da520cdcd4108c405304f SHA-1: 771364745e3777b2f558861cc5ed59464f7d18a0 SHA-256: 2bcb04dd74fc3d0de49336a93c821392cf6ddaecec03e2dc8250556ab41cd2d3
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to other PDF files, suggesting a link farm designed to improve search engine ranking for the primary malicious URL. The primary malicious URL, https://baarspo.ru/strik, is likely used for phishing or to serve further malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://baarspo.ru/strik?utm_term=mathematics+paper+2+calculator+1ma1%252F2f+answers+2015
    • https://static.s123-cdn-static.com/uploads/4489050/normal_5fc71e83038c9.pdf
    • https://puraxexi.weebly.com/uploads/1/3/4/7/134718411/pojokodap.pdf
    • https://bexokafosirur.weebly.com/uploads/1/3/2/6/132695536/lodaza_segatakabezogu_zutajulunumojok.pdf
    • https://cdn-cms.f-static.net/uploads/4483587/normal_6045f64e6f74d.pdf
    • https://static.s123-cdn-static.com/uploads/4366625/normal_5fcd6d8143055.pdf
    • https://molobaguzali.weebly.com/uploads/1/3/0/7/130739923/wopovizavon.pdf
    • https://cdn-cms.f-static.net/uploads/4459185/normal_6030cf96a905b.pdf
    • https://fikijumosoliz.weebly.com/uploads/1/3/5/4/135400707/12a7209580.pdf
    • https://static.s123-cdn-static.com/uploads/4372983/normal_5ffb270a4814f.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/wexukufedepim/jiwewuvelofud.pdf
    • https://uploads.strikinglycdn.com/files/4e6e7a4c-0052-4f65-9546-af7b56e954bf/sotukisoxuvusupo.pdf
    • https://uploads.strikinglycdn.com/files/8cee9dcf-cc05-448c-a943-400c9e7d0499/bufalifuzexat.pdf
    • https://s3.amazonaws.com/jalasilunaz/90144675619.pdf
    • https://s3.amazonaws.com/memobofilenabon/93860504655.pdf
    • https://s3.amazonaws.com/sajatesawodiji/jefasexorekabagezebov.pdf
    • https://s3.amazonaws.com/ganubifirigevi/app_lock_code.pdf
    • https://s3.amazonaws.com/befarekogol/zidevoxem.pdf
    • https://s3.amazonaws.com/rovuweraja/talif.pdf
    • https://uploads.strikinglycdn.com/files/c97c4d78-e3e5-43ac-b90e-5d98dff3e56e/nowexiwukukiwegomozuronax.pdf
    • https://s3.amazonaws.com/vuforewebub/64500804064.pdf
    • https://uploads.strikinglycdn.com/files/9d1d7313-04c9-4f14-ba35-f4ede86655c5/section_62_law_of_property_act_1925_explained.pdf
    • https://uploads.strikinglycdn.com/files/ce2adc41-7c97-4fd5-88b2-68a73bfa9651/rutixa.pdf
    • https://uploads.strikinglycdn.com/files/48dda7a1-4691-49ab-a074-d07441241bea/94420328261.pdf
    • https://s3.amazonaws.com/nosepevozux/verb_to_be_exercises_perfect_english_grammar.pdf
    • https://uploads.strikinglycdn.com/files/62c8a527-8d53-4698-a831-6931ed630757/resnick_fsica_volumen_1_5ta_edicin_solucionario.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_off000110ba.bin
a54e23209cb9e7a99dc10182971586247a6819280f00c3039dc4e79f5cff6061
pdf-font-stream PDF embedded font (sfnt) at offset 0x110BA 5836 bytes
font_01_sfnt_off0001249d.bin
d7c83c41b677bec57c31f6f3f9645d877d7c936486aff2331373b3da370bc757
pdf-font-stream PDF embedded font (sfnt) at offset 0x1249D 11168 bytes