Malicious PDF — malware analysis report

Static analysis result for SHA-256 91cce4b4636e429e…

MALICIOUS

PDF

84.5 KB Created: 2021-03-25 16:42:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 4c7fd36e08b413f77cb66b640e97b1ea SHA-1: 719dc6bfd3e018fb25da0c872668c1ef1640a797 SHA-256: 91cce4b4636e429e7193b54ebfb1d300915d06c8c34d9bf359b556adac61dd0c
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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.
  • 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://leonvi.ru/strik?utm_term=exploratory+multivariate+analysis+by+example+using+r+chapman+and+hall PDF link annotation
    • https://bemaxeviliw.weebly.com/uploads/1/3/4/4/134482954/3862754.pdfIn PDF document text
    • https://cdn.sqhk.co/posukomokufi/ifgglXl/gojimimozawotonadateso.pdfIn PDF document text
    • https://cdn.sqhk.co/mitejapeki/zpXhcic/keep_clean_cleaner_faster.pdfIn PDF document text
    • https://cdn.sqhk.co/zufuxirap/heEVFgg/sound_physicians_emergency_med_of_nv_bessler.pdfIn PDF document text
    • https://kerozuvesiduzam.weebly.com/uploads/1/3/4/3/134375161/7803148f39.pdfIn PDF document text
    • https://cdn.sqhk.co/luzigagoguna/jbanjay/53203246178.pdfIn PDF document text
    • https://cdn.sqhk.co/torujazelome/PigSnhh/gupumopuk.pdfIn PDF document text
    • https://waxosutuj.weebly.com/uploads/1/3/1/4/131437699/1a11e395077.pdfIn PDF document text
    • https://jakemujilofadam.weebly.com/uploads/1/3/1/3/131380171/8230102.pdfIn PDF document text
    • https://sixobeludid.weebly.com/uploads/1/3/5/2/135298518/tabuzivebag_zalubakisudenod.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/xezonijida/le_domande_pi_assurde_di_yahoo_answer.pdfIn PDF document text
    • https://s3.amazonaws.com/wezukep/how_to_make_origami_crane_with_normal_paper.pdfIn PDF document text
    • https://s3.amazonaws.com/najipavez/97094771496.pdfIn PDF document text
    • https://0dea665b-aaaa-42f3-a52c-f86f0fd1efa2.filesusr.com/ugd/8b9728_2c90fef577074db3aa250507abbaf4d0.pdf?index=trueIn PDF document text
    • https://6196a4e6-b3b5-4a85-a139-4ec84e0a53d9.filesusr.com/ugd/d01287_96f71e16d372483db550f0fafb228c3a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tanapilamaxi/demexolumigabum.pdfIn PDF document text
    • https://7f507849-5a67-47d8-9eb0-f7f10ac327ba.filesusr.com/ugd/cacfd7_9be6ec95992c4a3495bb4d128d61b12a.pdf?index=trueIn PDF document text
    • https://393102e6-89af-4738-8cad-89662dba8dc5.filesusr.com/ugd/33a16d_009300b326024c43a212bb5e4dab3197.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/lomuper/cushman_wakefield_office_market_report.pdfIn PDF document text
    • https://6c49ff76-e13b-46da-8354-2e633d56f736.filesusr.com/ugd/211c2d_9cf0d72fd49243c39dbb348a8a2a1c1d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gupojakami/how_make_a_toga_out_of_a_sheet.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_off000105d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D8 5816 bytes
SHA-256: 3ab6d0f307617378c0d4fedcfb3adc0ad65d09e28502a4b5a4192f4314458108
font_01_sfnt_off00011984.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11984 12540 bytes
SHA-256: e5f0c372bdae0ffd349e70f77cf7282295525737e2f863e5a9934208763f6fe5