Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b0a753f82a37ba3…

MALICIOUS

PDF

77.2 KB Created: 2021-02-24 10:01:26 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-03
MD5: 1f61b610927391a188030859974c4891 SHA-1: 4008d02c455d6e3fe8751076f97a5894c8c1ab47 SHA-256: 4b0a753f82a37ba3359796fb9c2b550155e005e104db9d4de3c3dab95a730628
244 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded links, many of which point to disposable hosting or redirector services, indicating a link farm or phishing attempt. The primary malicious link identified is https://yafferge.ru/strik, which is flagged as a malicious redirector. The document's content is designed to appear as a helpful resource, but its true purpose is to drive traffic to potentially harmful websites.

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://yafferge.ru/strik?utm_term=how+to+learn+cooking+basics In PDF document text
    • https://cdn-cms.f-static.net/uploads/4477629/normal_6023c9d2dec6e.pdfIn PDF document text
    • https://pudijamarotu.weebly.com/uploads/1/3/4/0/134000536/455526.pdfIn PDF document text
    • https://nizerekudoni.weebly.com/uploads/1/3/5/3/135383630/waturomaba.pdfIn PDF document text
    • http://7gusevshop.space/mario_kart_arcade_gp_downloadw60od.pdfIn PDF document text
    • https://wupixizot.weebly.com/uploads/1/3/5/3/135398135/jeparatisemodo.pdfIn PDF document text
    • http://particulier-societegenerale.xyz/dog_wallpaper_full_hd_downloadyvxxy.pdfIn PDF document text
    • https://zavisedifigi.weebly.com/uploads/1/3/4/3/134316550/83c3d.pdfIn PDF document text
    • https://pinozawekik.weebly.com/uploads/1/3/4/5/134589254/6484469.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404292/normal_6022ee5cdbf40.pdfIn PDF document text
    • http://copyright-central-media.com/netubenusovivyfyu.pdfIn PDF document text
    • http://tobubolixej.iblogger.org/behringer_xenyx_q1202usb_mixer_manual.pdfIn PDF document text
    • https://gumakamatiz.weebly.com/uploads/1/3/4/6/134600955/91e1abd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4382187/normal_5fe34e50c8d6b.pdfIn PDF document text
    • https://pibigetikuke.weebly.com/uploads/1/3/5/3/135387636/8bcf206f2899d0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471988/normal_5fd268aa586af.pdfIn PDF document text
    • https://lojapajarete.weebly.com/uploads/1/3/4/5/134521209/5707665.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sujidise.epizy.com/stayin_alive_chords.pdfIn PDF document text
    • http://kafudunafow.epizy.com/editable_weekly_meal_planner_template_word.pdfIn PDF document text
    • https://s3.amazonaws.com/fuvidokibet/vuvuwakerewudijorusotizat.pdfIn PDF document text
    • https://s3.amazonaws.com/debamijizozexo/arya_2_movie_songs_naasongs._com.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_off0000f324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF324 5224 bytes
SHA-256: da0af1d0d95b97c54041f11c84c94556555441d34b4e840be3baf32317d5096d
font_01_sfnt_off00010504.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10504 10120 bytes
SHA-256: 753347e13fd7347673b30fea056ea6f4c842d958a723d2b9ebb6047ff7b20d8b