Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab99272c0aa1be5c…

MALICIOUS

PDF

92.5 KB Created: 2021-05-23 08:14:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9ab0d057eaf0b036054c873b1f0f27ac SHA-1: 2f7f0feb4d919105fd850e43607480af6234413c SHA-256: ab99272c0aa1be5c3dd993b1b06110093bf830cb7fbad0f4740fb7852e83a657
214 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for linking to known malicious redirector infrastructure, specifically the URL https://yafferge.ru/strik. Additionally, it exhibits characteristics of a PDF link farm, embedding numerous external links, many of which are unknown or potentially malicious. The ML classifier also strongly flagged this PDF as malicious. These indicators suggest the document's primary purpose is to redirect users to harmful sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=best+custom+rom+for+huawei+mate+10+pro
    • https://cdn-cms.f-static.net/uploads/4388156/normal_6066762fba007.pdf
    • https://juwomazitebuden.weebly.com/uploads/1/3/1/4/131414743/megepelodu.pdf
    • https://static.s123-cdn-static.com/uploads/4369512/normal_5febd1e5def4a.pdf
    • https://static.s123-cdn-static.com/uploads/4403814/normal_5fe3c5936dada.pdf
    • https://static.s123-cdn-static.com/uploads/4443578/normal_5fdf6873be886.pdf
    • https://redefanugolikiz.weebly.com/uploads/1/3/5/9/135975275/dujopaw_vanivox_mixupubosube.pdf
    • https://nabaduvikarupad.weebly.com/uploads/1/3/4/0/134096068/5665730.pdf
    • https://tejaxoxujita.weebly.com/uploads/1/3/4/3/134368030/c57a43107e169a7.pdf
    • https://static.s123-cdn-static.com/uploads/4483854/normal_5fe062afe1896.pdf
    • https://judurufag.weebly.com/uploads/1/3/4/6/134688768/fudabagigum.pdf
    • https://tojisoma.weebly.com/uploads/1/3/5/3/135330836/kedoropufav.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/4c7185e5-8fad-4fa9-b0a6-cb8e15b832b3/spektrum_dx5e_simulator_cable.pdf
    • https://uploads.strikinglycdn.com/files/372830a1-2161-44c0-9467-ad9fb1d96ce9/3096372720.pdf
    • https://uploads.strikinglycdn.com/files/be7d5d22-b54e-4ec1-8fc2-fee6fb06e68d/best_comic_books_for_3rd_graders.pdf
    • https://uploads.strikinglycdn.com/files/ceee74db-7d0f-49ab-b638-012a0b207ac6/microsoft_sculpt_comfort_keyboard_user_guide.pdf
    • https://uploads.strikinglycdn.com/files/c0929393-8458-42a9-9db9-bb5a1ddb03bf/80141162552.pdf
    • https://uploads.strikinglycdn.com/files/cfb8da57-53a8-45dc-ae0c-37b321595b56/how_to_complete_summary_in_ielts_reading.pdf
    • https://uploads.strikinglycdn.com/files/e6edb561-cdf5-4812-ba59-0c40410e9c51/26928599693.pdf
    • https://uploads.strikinglycdn.com/files/dbd2760d-a06b-49fe-919e-e99b5bfca94d/how_to_work_mophie_juice_pack_air.pdf
    • https://uploads.strikinglycdn.com/files/94d52b5f-7b47-48cf-8a65-b833183660e6/59666118411.pdf
    • https://uploads.strikinglycdn.com/files/8ef79803-0d4c-4a5f-8d34-49e22a3d3445/english_101_syllabus_2019.pdf
    • https://uploads.strikinglycdn.com/files/51b3c32d-a2e3-472e-9ce1-ade5ffadcbb6/negexujiz.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011dc0.bin
1baa3efd180cf5f44d613abe34ea0380c2d25dd221f4ef864ac418d56f73cc35
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DC0 2912 bytes
font_01_sfnt_off0001281c.bin
2f97592f843b3435d5ae23bcdc25771eb7a91d89f3516c4b67809282b2f2ddeb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1281C 5556 bytes
font_02_sfnt_off00013af4.bin
65086f46e1b65cd21877921d88550f7b6c2fc7b4ba59406f1c2e0f9f639193dc
pdf-font-stream PDF embedded font (sfnt) at offset 0x13AF4 11972 bytes