Malicious PDF — malware analysis report

Static analysis result for SHA-256 831c3d210870c05e…

MALICIOUS

PDF

91.9 KB Created: 2021-04-21 17:49:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 396c430cddde606e43d54b67c05f36fa SHA-1: b39adeb5318de33c4927b60d0f5f71bb8aa2796d SHA-256: 831c3d210870c05e8cabe11b362d2f691585705b99a8594f20f102f979bc027c
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm designed to redirect users to numerous external sites. The presence of multiple PDF links and disposable hosting suggests an attempt to obscure the ultimate destination, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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
  • 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://pelibifir.ru/strik?utm_term=mental+toughness+navy+seal+book PDF link annotation
    • https://cdn.sqhk.co/letojeka/gjc5Yih/nutukumipozovudigi.pdfIn PDF document text
    • http://ratedewu.scienceontheweb.net/human_genetic_variation.pdfIn PDF document text
    • https://cdn.sqhk.co/dojaxeje/hihdfjc/72528860129.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470835/normal_6028ee316cb54.pdfIn PDF document text
    • http://gilumesu.mypressonline.com/67570338116.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4377933/normal_5febc3a751547.pdfIn PDF document text
    • https://zofifonanofanap.weebly.com/uploads/1/3/4/8/134876640/kagojen_bomokegatakog_pebesixoweti_xekividapavena.pdfIn PDF document text
    • https://cdn.sqhk.co/xenivoronizu/pCjjcjc/rumijidibedegexiwixipusi.pdfIn PDF document text
    • https://fivubiforozoxi.weebly.com/uploads/1/3/4/6/134676017/xasebej.pdfIn PDF document text
    • https://cdn.sqhk.co/ladesajisama/ifhTjjd/43945893403.pdfIn PDF document text
    • https://cdn.sqhk.co/pusuvizodez/rNS9gcU/jovaxesef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422631/normal_603b5bd3d9576.pdfIn PDF document text
    • http://jidugisukeranav.iblogger.org/dyson_dc18_slim_parts.pdfIn PDF document text
    • https://kunobutos.weebly.com/uploads/1/3/4/2/134234797/jiteziboxotozev_lavunut.pdfIn PDF document text
    • https://pisukobuvasojab.weebly.com/uploads/1/3/4/3/134398412/1698007.pdfIn PDF document text
    • https://cdn.sqhk.co/pozuwifofub/ii0jfhh/jumpstart_definition_synonym.pdfIn PDF document text
    • https://cdn.sqhk.co/baxikomo/Wjhgdf6/52780749250.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://gizolejonig.rf.gd/banking_chronicle_free_download_november_2020.pdfIn PDF document text
    • http://nikixoza.epizy.com/home_brew_beer_greg_hughes.pdfIn PDF document text
    • http://wukerakowevomu.epizy.com/32258046642.pdfIn PDF document text
    • http://julisanusifi.rf.gd/hello_app_video_mp4.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011c5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C5C 5056 bytes
SHA-256: 61ed911b70e23b3049794feab0f5ff02519f91052f16bb0fb9da97fdadd709ac
font_01_sfnt_off00012da3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DA3 11404 bytes
SHA-256: 759825e6efc904c2887c4700bd503d23b16d0a566fa8647a26870ecdcee268e5
font_02_sfnt_off00015418.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15418 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2