Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1549911c497b0dd…

MALICIOUS

PDF

114.6 KB Created: 2021-04-25 02:45:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fe79a8ff27de6e61c511f0d9cc7f401d SHA-1: b76c0595263c072330493fbb2c768d429928d9eb SHA-256: b1549911c497b0dd3455860a8b8c35d5adcf297587a01765a7add0d5d04a0b93
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying it as a PDF SEO link farm. One of the primary external links, 'https://dafemum.ru/strik?utm_term=second+hand+law+textbooks+uk', suggests a lure to a website disguised as a search result. ClamAV detection and ML classification strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://dafemum.ru/strik?utm_term=second+hand+law+textbooks+uk
    • https://static.s123-cdn-static.com/uploads/4473432/normal_5ff11aae3ba34.pdf
    • https://cdn-cms.f-static.net/uploads/4389570/normal_6057b35cf02fe.pdf
    • http://xodulik.66ghz.com/93902018039.pdf
    • http://tavaxibewoposo.iblogger.org/nunatuxugegokavujokabe.pdf
    • http://jotipire.iblogger.org/extracorporeal_life_support_organization_guidelines.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/fuwawibu/4909943551.pdf
    • https://55963656-6eb1-4b25-bcd5-bb835d65808b.filesusr.com/ugd/0064ae_662cfefd1ad04f43b74b3c5b556e4fe7.pdf?index=true
    • https://s3.amazonaws.com/rokuwapesu/fijilavibetamaxoxuk.pdf
    • http://xamupufe.epizy.com/topejuwixira.pdf
    • http://temelozorijaxi.epizy.com/duxonojuto.pdf
    • https://ecab545c-19d2-4654-b6ac-fb8b9749f5ba.filesusr.com/ugd/e5412a_a11a0da575eb4772aa5ca32fbc86373e.pdf?index=true
    • https://s3.amazonaws.com/jitimesolagun/what_are_the_elements_of_differentiated_instruction.pdf
    • https://s3.amazonaws.com/lolaritemukole/narawipadikizatubi.pdf
    • https://s3.amazonaws.com/lorifumofelu/wapavur.pdf
    • https://s3.amazonaws.com/memobofilenabon/89115511152.pdf
    • https://s3.amazonaws.com/nitajosasa/xufubogeraxagobibutevoba.pdf
    • https://d0fd22f1-78bd-4368-960d-2a324028b2bb.filesusr.com/ugd/a4d998_95de4ae78940463abdca107c47bd7250.pdf?index=true
    • 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_off0001855e.bin
0c5d5890788982b91d3ccf199727178d4eb98f0306bef1592d5fe22cecd155c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1855E 5400 bytes
font_01_sfnt_off000197cb.bin
ea383864269e71e7eb33aa35d89e3c5a2d63c49f59be99c8c1e1d9d86c302250
pdf-font-stream PDF embedded font (sfnt) at offset 0x197CB 11192 bytes