Malicious PDF — malware analysis report

Static analysis result for SHA-256 77ec1cda7b77b383…

MALICIOUS

PDF

86.5 KB Created: 2021-05-01 13:49:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f9cc3c609c7302dd5cea2cdb508e8083 SHA-1: c26308d80153dd25322219cdc77694ed141e3534 SHA-256: 77ec1cda7b77b383e41b3edefc2900a03c5b2c8347947ff2046eb8b203b20e04
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to PDF files hosted on various domains, indicative of a link farm. One prominent URL, 'https://bologen.ru/strik?utm_term=20000+leagues+under+the+sea+1997+movie+review', acts as a redirector, likely for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent, specifically phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://bologen.ru/strik?utm_term=20000+leagues+under+the+sea+1997+movie+review PDF link annotation
    • https://taxajoberaruvu.weebly.com/uploads/1/3/4/3/134320235/166305.pdfIn PDF document text
    • http://kemikavar.mypressonline.com/airstream_nest_brochure.pdfIn PDF document text
    • http://kogutojoveso.mywebcommunity.org/acquisitions_incorporated_google_drive.pdfIn PDF document text
    • https://vopezewom.weebly.com/uploads/1/3/3/9/133988608/vajoxukilibonakifa.pdfIn PDF document text
    • http://xevusezes.medianewsonline.com/az_103_exam_dumps.pdfIn PDF document text
    • http://fegiroxopirez.sportsontheweb.net/how_do_i_get_my_turtle_beach_headset_to_work_on_my_pc.pdfIn PDF document text
    • https://mivewuwadomabat.weebly.com/uploads/1/3/1/6/131606259/xifakotitop_xilopilezivom_senedonezak_niwesiwifokex.pdfIn PDF document text
    • http://napodosawukezob.getenjoyment.net/bfs_algorithm.pdfIn PDF document text
    • https://tonuvufew.weebly.com/uploads/1/3/1/4/131438708/4570752.pdfIn PDF document text
    • https://girawosanisab.weebly.com/uploads/1/3/0/7/130740609/8af868dc72bb4c.pdfIn PDF document text
    • http://wupidubame.mywebcommunity.org/alternatives_conomiques_reussir_son_bac_es_2020.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
    • https://s3.amazonaws.com/midizaxopazeji/najubumegejusawume.pdfIn PDF document text
    • https://s3.amazonaws.com/papuja/46440578598.pdfIn PDF document text
    • https://s3.amazonaws.com/gazitif/phenylketonuria_review.pdfIn PDF document text
    • https://s3.amazonaws.com/vinivuxo/asme_journals_free.pdfIn PDF document text
    • https://s3.amazonaws.com/jarirotexab/momudimux.pdfIn PDF document text
    • http://jolivawojo.rf.gd/date_format_in_rdlc_report_expression.pdfIn PDF document text
    • http://fiforeru.atwebpages.com/keto_cookbook.pdfIn PDF document text
    • http://dozopedatofol.atwebpages.com/xekodegotizexafune.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_off00010499.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10499 5740 bytes
SHA-256: 590bd6002b7a13dfc60296944d351e0008a7c72d6dc7fde33ed7b2f66d1c8d20
font_01_sfnt_off00011808.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11808 11384 bytes
SHA-256: b9e20e36ff35a32f017c15a904f507015307fbd75f0fe286abe2815125ed895b
font_02_sfnt_off00013e80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E80 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378