Malicious PDF — malware analysis report

Static analysis result for SHA-256 79fe319a03cb79b3…

MALICIOUS

PDF

89.8 KB Created: 2021-03-20 23:44:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: f5a9731751683cb68a0b425a65017f85 SHA-1: bbac00b9cef33169cc9076805a943d4db4959b90 SHA-256: 79fe319a03cb79b3285f698eaddc77a4aa2c89c11cec12c9d60e64f2e5d135e5
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, identified as a "PDF_SEO_LINK_FARM" and "PDF_SEO_UTM_REDIRECTOR_LINK", suggesting a tactic to manipulate search engine results or redirect users to malicious sites. The primary URL, "https://druttle.ru/wix?keyword=geometry+chapter+6+test+answer+key", is presented as a lure for educational content. While no scripts were extracted, the PDF structure and URL patterns strongly indicate a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://druttle.ru/wix?keyword=geometry+chapter+6+test+answer+key PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4382952/normal_5fe55911e3730.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465147/normal_5fd84e3c3fb10.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390324/normal_602a6e89c2e91.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452199/normal_5fddf62e5eb38.pdfIn PDF document text
    • http://tumuduwaju.mypressonline.com/4th_grade_multiplication_word_problems_grade_4.pdfIn PDF document text
    • http://jawixogu.mygamesonline.org/how_to_get_percentile_rank_in_excel.pdfIn PDF document text
    • http://xomutukegadoj.mypressonline.com/41210891321.pdfIn PDF document text
    • http://bipowilago.mywebcommunity.org/juborenufifaxijigux.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://josesomesube.myartsonline.com/velerirep.pdfIn PDF document text
    • http://bibezakomi.myartsonline.com/kabajawudusogapitobim.pdfIn PDF document text
    • https://s3.amazonaws.com/natewared/39801846587.pdfIn PDF document text
    • https://6a1e2a5f-c456-4288-b9d5-5378f87870fb.filesusr.com/ugd/076fac_960da59809bc43cb99df7788553a59fa.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xumakomowi/how_long_does_a_dell_latitude_battery_last.pdfIn PDF document text
    • https://s3.amazonaws.com/makumapikeze/xelibipivefarimas.pdfIn PDF document text
    • https://s3.amazonaws.com/pulavokaxe/vafilip.pdfIn PDF document text
    • https://78151a86-a557-4e49-81aa-a2539eea45c7.filesusr.com/ugd/204f4f_461e32744e0448bfaaca37d3ea173aef.pdf?index=trueIn PDF document text
    • https://dfa52777-3edb-460f-9b14-ca5101cd4ecc.filesusr.com/ugd/5360f8_4ddf74e451764c6894f5d13598162a11.pdf?index=trueIn PDF document text
    • http://pozidijapepore.atwebpages.com/brian_tracy_eat_that_frog_amazon.pdfIn PDF document text
    • http://miganuvag.myartsonline.com/business_policy_and_strategic_management_case_study_with_solution.pdfIn PDF document text
    • https://s3.amazonaws.com/tabobujimo/ejercicios_con_verbos_regulares_en_pasado_en_ingles.pdfIn PDF document text
    • https://s3.amazonaws.com/zowibatev/waterpik_cordless_advanced_water_flosser_wp-562.pdfIn PDF document text
    • https://95fbbc11-640f-4658-acdf-6e09da746871.filesusr.com/ugd/e42ee3_c502688b0ff9401ba39b155eb6d37db8.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/juzowilipi/android_browser_intent_not_working.pdfIn PDF document text
    • https://s3.amazonaws.com/zebarufuridorur/cadillacs_and_dinosaurs_apk_free.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f84b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84B 5324 bytes
SHA-256: f6c5a0f3b121d1f95950b9a8a305b6c3733e3c1fcb5a006cb5fae6da89cc137e
font_01_sfnt_off00010a52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A52 12632 bytes
SHA-256: c226292b6de7af6d55770a9ca24743109cf76a0e38d99a76f94b93271ae13f21
font_02_sfnt_off00013534.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13534 16284 bytes
SHA-256: c54d53ff9e0aa22c358b782aded171f1909958938abc54ff4c6aaee6090e660a
font_03_sfnt_off00014acb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ACB 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230