Malicious PDF — malware analysis report

Static analysis result for SHA-256 4162d0bc9777dd3b…

MALICIOUS

PDF

80.6 KB Created: 2021-05-07 19:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 8746ce81dee78d39b2dd8f8121ca7521 SHA-1: d6e79868d351de80e230585e96c64786b982c87f SHA-256: 4162d0bc9777dd3b219a43c5da4885014dcecee66501267390fa69a6e0b34aea
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which are part of an SEO link farm designed to redirect users to malicious sites. The primary redirector URL is https://jottigo.ru/strik?utm_term=play+the+song+memories+bring+back+memories+bring+back+you, which is likely used for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://jottigo.ru/strik?utm_term=play+the+song+memories+bring+back+memories+bring+back+you PDF link annotation
    • http://tetupamino.mywebcommunity.org/44166041961.pdfIn PDF document text
    • http://lenugaguv.medianewsonline.com/9813948113.pdfIn PDF document text
    • http://kafalukuwemi.mygamesonline.org/lidemivarixabevisufi.pdfIn PDF document text
    • http://nuwojukow.mygamesonline.org/88220403449.pdfIn PDF document text
    • http://jusojixanona.getenjoyment.net/cisco_discovery_protocol.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/setikizo/sixojujazor.pdfIn PDF document text
    • https://s3.amazonaws.com/sepovutapakogaf/jokem.pdfIn PDF document text
    • https://25cf7bc6-226b-4013-96fa-c64d334b7dac.filesusr.com/ugd/317e1a_c87caf10eb7a4c8cafdb54ee58af3956.pdf?index=trueIn PDF document text
    • https://184d393c-d2ff-49e5-bbcb-48626b1dbf88.filesusr.com/ugd/49be48_7175b56474734dd29191d95b27afa503.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wifiduxezo/compare_and_contrast_two_working-class_works_of_art.pdfIn PDF document text
    • https://4c5ad993-366d-4b3a-aa99-9b6f56583180.filesusr.com/ugd/01e791_3c24d12fee2a45c19a3bbca1569f5f80.pdf?index=trueIn PDF document text
    • http://zitejilid.epizy.com/60398865596.pdfIn PDF document text
    • https://f18b8dc1-3ce9-44bd-8712-01435d039869.filesusr.com/ugd/b97cba_64b3a1fac3154cb989d33321f4d509eb.pdf?index=trueIn PDF document text
    • https://5090cb7a-f7dd-45b7-a4a3-960150b62b23.filesusr.com/ugd/dfd4af_82ee675cc8264caa94b64aa19b02f3a3.pdf?index=trueIn PDF document text
    • https://9534cc33-30dc-483d-bed2-8d5691710d48.filesusr.com/ugd/3835dd_9379608b1f3c44d199eb8d69f645fbd5.pdf?index=trueIn PDF document text
    • https://0f8fedcd-12c0-4678-86f8-e2bff7269121.filesusr.com/ugd/70e7d4_98c2659709a0450eb7bc6c2555c1a2a4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nabifovu/blood_pressure_medication_recall_list.pdfIn PDF document text
    • https://s3.amazonaws.com/lolijexejomak/96167411922.pdfIn PDF document text
    • https://s3.amazonaws.com/fadadedezeker/proforma_invoice_word_template.pdfIn PDF document text
    • https://s3.amazonaws.com/wizakokowe/honda_express_for_sale_uk.pdfIn PDF document text
    • http://bokakemipik.epizy.com/jump_force_switch_dlc_release_date.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_off0000fc79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC79 5520 bytes
SHA-256: b8b773270866f3e2ae2c6a4af0b094591c06afa1a89e221dc4b9c33e528da0c5
font_01_sfnt_off00010f22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F22 11108 bytes
SHA-256: 8d6019a706c93499a95a6846e01aa20868e4bdc50f5a4b2279f473bcb7716de3