Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa4edaf8128dc2a8…

MALICIOUS

PDF

78.5 KB Created: 2021-03-10 14:20:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2693276999d1ef163a6db6aab2fd906c SHA-1: 258f37ce74d69d4be929d95b87ceec33d407cf3c SHA-256: aa4edaf8128dc2a8a5e33d4dc6f8920e922be4eb7911118683a0425e6e06c4f0
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are dynamically generated, indicating a link farm for SEO manipulation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for distributing further malware or phishing content. While no scripts were explicitly extracted, the PDF structure and numerous external URLs point towards a malicious distribution or redirection mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nipisod.ru/award?keyword=airborne+electromagnetic+survey+pdf
    • https://cdn.sqhk.co/pimidima/hinjjiI/pixez.pdf
    • https://cdn.sqhk.co/wabasenenem/kheljhg/vector_quantity_physics_wallah.pdf
    • https://cdn.sqhk.co/fujotojaxob/TjiTnig/telegram_desktop_voice_call.pdf
    • https://solupufaposedi.weebly.com/uploads/1/3/1/8/131857421/vixomote-patujiriwajadu.pdf
    • https://mabelobixos.weebly.com/uploads/1/3/4/6/134621829/16e0b848ba3fe5c.pdf
    • https://cdn.sqhk.co/wimiwupo/gfhiZ5f/viwulovosedanobin.pdf
    • https://cdn.sqhk.co/mujejadalale/shchbx3/nevijawif.pdf
    • https://xarupome.weebly.com/uploads/1/3/4/4/134469096/gudobifevewaki-tonamekijizumu.pdf
    • https://vonosupaxeme.weebly.com/uploads/1/3/0/7/130740497/niwuverilonomim.pdf
    • https://rudiwiguxovo.weebly.com/uploads/1/3/5/3/135317070/844f8.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/nedijowewoded/homeschool_attendance_sheet.pdf
    • https://s3.amazonaws.com/zijivevip/65396167168.pdf
    • https://b6e49935-6d58-4bde-831f-6e0b746776d3.filesusr.com/ugd/7d321f_1d2460bb238f470b95f7d2c34ee88503.pdf?index=true
    • https://4f0754e2-f0c4-47db-826b-83042027646c.filesusr.com/ugd/7a11b0_c300b87bf9124506b18e96f55b4c0060.pdf?index=true
    • https://s3.amazonaws.com/jeduzizonox/rodrigo_concierto_de_aranjuez.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6b6.bin
e3bab6b03f9fcf7df114afc63b55c043ff01c3e3e1d772df8e3ee6ceb87d9c26
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B6 5764 bytes
font_01_sfnt_off00010a51.bin
995fb8eee6f8909604bffd4afd03020d648312aba20f18bd3ff23b41b89ed2ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A51 10032 bytes