Malicious PDF — malware analysis report

Static analysis result for SHA-256 99338214a7fb0790…

MALICIOUS

PDF

75.3 KB Created: 2021-05-29 14:41:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 16b6696fea8efe6db087cdf5588b10df SHA-1: 45cf6f23c6ad2772eab88884d94471faabf883bf SHA-256: 99338214a7fb079009198c24f9fe45e699875c3e2674a1f8d85fb20690abf53a
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, a technique often used for SEO poisoning or to redirect users to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as a phishing trojan. The primary URL, https://kuzutuzo.ru/strik, is likely the malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kuzutuzo.ru/strik?utm_term=angulos+en+posicion+normal+ejercicios+resueltos+pdf
    • https://cdn-cms.f-static.net/uploads/4454673/normal_60204aedcbd9b.pdf
    • https://cdn-cms.f-static.net/uploads/4485807/normal_60329b5518ba9.pdf
    • https://static.s123-cdn-static.com/uploads/4371258/normal_5ffc8f611b001.pdf
    • https://cdn-cms.f-static.net/uploads/4369304/normal_60186d9766590.pdf
    • https://gabixolip.weebly.com/uploads/1/3/4/4/134492453/ee7cf5fac.pdf
    • https://static.s123-cdn-static.com/uploads/4446930/normal_5fe08bb411c5b.pdf
    • https://static.s123-cdn-static.com/uploads/4481528/normal_5fe0d79b8c4a1.pdf
    • https://cdn-cms.f-static.net/uploads/4370266/normal_603723ec6031d.pdf
    • https://nukanepinax.weebly.com/uploads/1/3/1/4/131454046/68dac.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/23572a22-6386-4d39-a046-8d003c70df26/iphone_ringtone_mp3_free_download_for_android.pdf
    • https://uploads.strikinglycdn.com/files/fd3d8eef-8991-4da5-821e-86aa0ba40593/84792363498.pdf
    • https://uploads.strikinglycdn.com/files/bb824d02-8006-4b0d-bb1f-4762775ef545/how_to_insert_cleaning_solution_in_swiffer_wet_jet.pdf
    • https://uploads.strikinglycdn.com/files/b5c4b97e-1702-4ee9-a58a-62c73a4b452d/51549042761.pdf
    • https://uploads.strikinglycdn.com/files/67d0a6dd-7b0b-404e-8549-e2d2d21fea40/chuck_palahniuk_best_books.pdf
    • https://uploads.strikinglycdn.com/files/b9ff89ab-20ae-458e-bce8-e2287bbe2290/whirlpool_self_cleaning_water_dispenser_not_cooling.pdf
    • https://uploads.strikinglycdn.com/files/21a2f7bd-56d1-4756-b903-fda7f6db12d4/follow_instructions_skills.pdf
    • https://uploads.strikinglycdn.com/files/87621dbd-eae5-4a55-94ec-25b8fa0102bd/kebaxedisala.pdf
    • https://uploads.strikinglycdn.com/files/dd221dbc-f5c7-4f84-8c8e-00c692a5656c/dell_c1765nfw_mfp_laser_printer_driver.pdf
    • https://uploads.strikinglycdn.com/files/499fb3ab-de7e-40ab-b7f0-e3097f8e7dd0/bibenanom.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c558.bin
820f14fb3c39b4b5b66da2fbfdc5f7bd8ed2ab36704c8d7947f18d58830d4503		 pdf-font-stream PDF embedded font (sfnt) at offset 0xC558 5540 bytes
font_01_sfnt_off0000d822.bin
4083f3fb55103a9595d7293c06d7e059314b57aa26d550a0078c3ddbc09e3cc8		 pdf-font-stream PDF embedded font (sfnt) at offset 0xD822 2256 bytes
font_02_sfnt_off0000e1aa.bin
d150032450bfb9e898fef3cab57d82a82c3f000ec803aa15aad59c42b2c2deb7		 pdf-font-stream PDF embedded font (sfnt) at offset 0xE1AA 11356 bytes
font_03_sfnt_off00010768.bin
1e8a0bdb875ec4e4f3103cebe592147bc93d99ac11ab0dcee4d91369816bca4e		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10768 16316 bytes

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