Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d53a7e7d5be6f40…

MALICIOUS

PDF

70.9 KB Created: 2021-09-14 03:48:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f4abdc4016b88ee2695a4fcdfa84c439 SHA-1: 61a546f3b2ca02c06a6ce67a8bd13f71aaf94a96 SHA-256: 6d53a7e7d5be6f40fefd56096d72a636bbb4b9d6f392bf1a20a5f60449bc7421
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristic firings indicating malicious intent, including random and disposable link farms pointing to external URLs. ClamAV also detected it as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially malicious content, likely as part of a phishing or malware delivery scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://krisoc.ru/uplcv?utm_term=digital+forensics+pdf PDF link annotation
    • http://jeanchapleau.com/userfiles/file/vewofipiwuxaradobavevil.pdfIn PDF document text
    • https://www.elshandmadedesign.nl/ckfinder/userfiles/files/61242393394.pdfIn PDF document text
    • http://healthywithhart.com/res/file/kegojerobexakiburis.pdfIn PDF document text
    • http://pmke.cz/pictures/files/86773039197.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/bibatovofifo.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/91769730802.pdfIn PDF document text
    • https://www.speeddating.lt/speeddating/ckfinder/userfiles/files/nevojesek.pdfIn PDF document text
    • https://ilexgold.com/app/webroot/files/userfiles/files/13475693927.pdfIn PDF document text
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/gixapakikopefe.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/disewizenoxozifaxamu.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210912224742.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/89659325630.pdfIn PDF document text
    • https://filetorme.com/upload/files/xojuzas.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/nakixafisufop.pdfIn PDF document text
    • https://zoomkish.com/basefile/zoomkishcom/files/79978162031.pdfIn PDF document text
    • http://qwerty.pl/_data/file/dupalivitogale.pdfIn PDF document text
    • http://cabinet-blin.fr/ressource/site-image/files/wutogetafowanazafokexu.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/e9ce75b9c0f7e9ac54cd860b530e6e02/31458176180.pdfIn PDF document text
    • https://illinoisfiscalpolicycouncil.org/app/webroot/userfiles/file/roxidodaxeriratulorusovo.pdfIn PDF document text
    • http://neboskreb-irk.ru/uploads/userfiles/files/59151063024.pdfIn PDF document text
    • http://keralatravelpath.com/uploads/file/6415682364.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1613477c2bdc0f---58217031078.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/legasibixifozuneseni.pdfIn PDF document text
    • https://skywaytravelandholidays.com/ckfinder/userfiles/files/24836685002.pdfIn PDF document text
    • https://kungfuclasshongkong.com/louis/taichi/ckfinder/userfiles/files/96964109002.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161348e2257480---getasurojofajexupalugo.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b5ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cdc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC3 10796 bytes
SHA-256: cd7ff5ab447169524255e3dbed6f9f77b38648e28a2411a6d4013a5c15802389
font_02_sfnt_off0000e68a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE68A 15588 bytes
SHA-256: b5f53772c21ef5fee8ec7cba8cdb4d68ec84e249b5d903ccdbd5ca6d619a8ab7