Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff2b9afab3224ae7…

MALICIOUS

PDF

79.2 KB Created: 2021-05-19 20:48:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: b9eb5c926404480f2c9e7529d7dec6f1 SHA-1: cd13494df56ae18776ac4cb7335a820b4b0d5f5a SHA-256: ff2b9afab3224ae758290fa75873c3bf1165a38978e2dad43c4947eeff12ce85
196 Risk Score

Malware Insights

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

This PDF document contains a large number of external links, many of which point to SEO-optimized content farms. The primary malicious URL identified is https://jacksth.ru/strik, which appears to be an SEO redirector used for phishing or malware distribution. The PDF_SEO_LINK_FARM heuristic indicates a mass of external links, and the ML classifier strongly suggests maliciousness, aligning with a phishing or trojan delivery attempt.

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://jacksth.ru/strik?utm_term=how+to+find+n1+and+n2+given+wavelength PDF link annotation
    • https://lezogujivezubix.weebly.com/uploads/1/3/4/8/134878846/siganex_wemuri.pdfIn PDF document text
    • https://bazamafew.weebly.com/uploads/1/3/4/0/134016738/didoles.pdfIn PDF document text
    • https://didosetugub.weebly.com/uploads/1/3/1/6/131606008/niwif.pdfIn PDF document text
    • https://sizugive.weebly.com/uploads/1/3/5/9/135993047/tuvijenew.pdfIn PDF document text
    • https://wunurobi.weebly.com/uploads/1/3/4/8/134881210/zipugewikoluzoru.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/wunupalezozerud/identify_these_dog_breeds_quiz_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/jivuxo/tunibefagubirezaboluza.pdfIn PDF document text
    • https://s3.amazonaws.com/towutoginadivu/bovenupabaguj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0953ca76-19a3-473b-9b3f-66e2f9fcc8d9/fender_mustang_1_amp_settings.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ccdb22f-e00f-4f5b-b382-3e5d69d4049b/27480712070.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/37f0b93b-27f4-4855-a5b9-416e34a88dea/2879010053.pdfIn PDF document text
    • https://s3.amazonaws.com/xijalovelokolep/sentry_safe_1170_replacement_lock.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/633c441d-dc6a-4c0b-9a3e-6a55267a9cd3/honeywell_programmable_light_switch__motor_timer_instructions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb9c3500-815c-4878-8f7b-aed0d3b7f2a1/forekodetanorilejuzane.pdfIn PDF document text
    • https://s3.amazonaws.com/loranoduzuja/crossword_answer_for_excessively_sentimental.pdfIn PDF document text
    • https://s3.amazonaws.com/gisujubolidine/zetodu.pdfIn PDF document text
    • https://s3.amazonaws.com/xedewofuretujo/biology_book_10th_grade_online.pdfIn PDF document text
    • https://s3.amazonaws.com/nefomojuwet/57514978529.pdfIn PDF document text
    • https://s3.amazonaws.com/zifilobesumafi/que_se_puede_comer_con_el_potasio_alto.pdfIn PDF document text
    • https://s3.amazonaws.com/rovikibixu/biometric_attendance_system_software.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35636eec-898a-47ae-ac17-d4f6dbb75f0e/adobe_premiere_pro_2.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_off0000f59b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF59B 5192 bytes
SHA-256: 110c15dedc9293111365e9bab3cee16c95dc64c14819aa0bcbdae1495d2d0082
font_01_sfnt_off00010767.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10767 11180 bytes
SHA-256: 337ad251d28651acf65953bc42ba9a61ebca7cab3e828c8e6fa321fe6e273b51