Malicious PDF — malware analysis report

Static analysis result for SHA-256 42c764780dca35e9…

MALICIOUS

PDF

79.7 KB Created: 2021-04-01 16:42:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: f57fdc4786fd6ff36b86ebbceb229cac SHA-1: 27fb1ac1f42ceea2abcf1dab24ff1261c07c15f0 SHA-256: 42c764780dca35e94a1e49c3b971aec7eafcc2e6fef22f084823f2e4227b30c4
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, many of which appear to be part of an SEO link farm designed to redirect users to malicious sites. The primary malicious URL identified is https://mezovuduw.ru/strik, which is presented as a workout resource but likely leads to a phishing page. The ML classifier and ClamAV detection strongly indicate malicious intent.

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.
  • 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://mezovuduw.ru/strik?utm_term=resistance+tube+workout+for+chest PDF link annotation
    • https://cdn.sqhk.co/joxutedunik/kjhjejc/kiki_s_delivery_service_disney_cast.pdfIn PDF document text
    • http://sobanurosu.22web.org/kokapenotanaw.pdfIn PDF document text
    • https://cdn.sqhk.co/zitibidino/91gg5ha/fuwesimosusatuz.pdfIn PDF document text
    • https://cdn.sqhk.co/dukosisevu/heifhfx/zojepir.pdfIn PDF document text
    • https://cdn.sqhk.co/nivopekodi/hcidbhh/dofalipugefazugiw.pdfIn PDF document text
    • https://cdn.sqhk.co/wibononuve/j0gjiCx/nigerian_gospel_music_worship_songs_vol_2.pdfIn PDF document text
    • http://muxonobugimaki.22web.org/88665278259.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ede36962-9452-4451-b182-fa4236ba9bc6.filesusr.com/ugd/83b1b3_4a0656a61d78483aa463ddef699a53d3.pdf?index=trueIn PDF document text
    • http://pobopujobezov.rf.gd/buwojojolu.pdfIn PDF document text
    • https://5a2ada08-5b6c-402a-b0df-3636415b461e.filesusr.com/ugd/434ae6_eb3338c5e7ee4956b869d23ee606096c.pdf?index=trueIn PDF document text
    • https://f06ae689-34e6-4fd9-b749-a5985747e370.filesusr.com/ugd/4117a9_0e88e1f65f6c4c32b4f918127c3409f9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zonebon/rocking_horse_winner_setting.pdfIn PDF document text
    • https://s3.amazonaws.com/runuzitexokol/reporting_results_repeated_measures_anova_spss.pdfIn PDF document text
    • https://s3.amazonaws.com/vutame/ruxomokupenegibawifufalaj.pdfIn PDF document text
    • https://s3.amazonaws.com/lanaladu/82773693361.pdfIn PDF document text
    • https://d102a0f2-001f-4998-bb0a-88ac30ac05b5.filesusr.com/ugd/771ea4_100fc91945c5487f82bb82fef88463f1.pdf?index=trueIn PDF document text
    • https://fb79ad55-22b5-4823-9538-35c71bbbd514.filesusr.com/ugd/ea423f_770b9b760ded4e1b811694383bb63758.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/regovadeje/72876878659.pdfIn PDF document text
    • https://7e005a1c-fb68-43c1-af83-b854b6a2d282.filesusr.com/ugd/dcfb95_445fcb2227854136911a162e1e1e25ba.pdf?index=trueIn PDF document text
    • https://9e269ae7-c3cf-4b9f-bde2-1d9be064b7bf.filesusr.com/ugd/139869_72a0f469a0244d87a95fa85ec034fe50.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vobuturinivi/99289740784.pdfIn PDF document text
    • https://s3.amazonaws.com/tapelu/33041382913.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fb8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB8C 5240 bytes
SHA-256: 3657dc33d615a2963c26ed60f010ba67111aff14c47012392cb35c372fedacbe
font_01_sfnt_off00010d78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D78 10396 bytes
SHA-256: ee727e077c6b751d58937c8004c877b662603352341fc0cf2bc21cabba33fb69