Malicious PDF — malware analysis report

Static analysis result for SHA-256 54d381a155cdc9c7…

MALICIOUS

PDF

78.6 KB Created: 2021-09-21 04:45:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 361bf14ddd891f259dcf528fed8e6b3f SHA-1: 3d603c026c201d9f8eaaa438d3933b164a25b0c6 SHA-256: 54d381a155cdc9c790f060512f35d63a4f3531bdb7c6cdc41c24488be00089f2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on distinct domains, indicating a link farm. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic and the high ML score strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://am-assets.com/aom/magnolia/userfiles/file/zurewigesubilenijumamexi.pdf In PDF document text
    • http://hsound.ro/images/custom/file/sumupa.pdfIn PDF document text
    • http://unitekinfostructures.com/userfiles/file/99124285836.pdfIn PDF document text
    • http://fygl.net/uploads/file/201224128536.pdfIn PDF document text
    • http://hoaiduc.edu.vn/ckfinder/userfiles/files/tezazadinijosapaxa.pdfIn PDF document text
    • http://degrossier.nl/uploads/file/46340210093.pdfIn PDF document text
    • http://www.jokilaaksonratsastajat.fi/file/91607000656.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/numuvuvupinet.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/64180389583.pdfIn PDF document text
    • http://salsainkonstanz.de/media/files/lapubifa.pdfIn PDF document text
    • http://mocphatreal.com/assets/images/ckfinder/files/jevowifowenofoxetuzopaza.pdfIn PDF document text
    • http://ckud.handysociality.com/upload/files/donesatudimizafubuvu.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/goxijesejepuwepu.pdfIn PDF document text
    • http://ankaser.com/userfiles/file/92799833374.pdfIn PDF document text
    • https://grouptm2.com/contents/files/78065468470.pdfIn PDF document text
    • https://find-domain.lazy-online-shop.com/app/webroot/userfiles/files/durefu.pdfIn PDF document text
    • http://aspbae.org/userfiles/file/vositivaluxalalokif.pdfIn PDF document text
    • https://marcuspietrek.de/MARCUS/files/file/30018662660.pdfIn PDF document text
    • http://metaglas.kr/userData/board/file/luvosukedunowerivazazo.pdfIn PDF document text
    • http://marketingnews.fr/images/file/jufaluvususuxe.pdfIn PDF document text
    • https://etevent.itweald.com/uploads/files/613f41632a281.pdfIn PDF document text
    • http://magdrywall.com/project-new/christianbook/upload_images/file/78200670622.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/79000279529.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/17869201371.pdfIn PDF document text
    • http://thekitchendesignstudio.org/uploads/files/53330080803.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/wojifofisokubo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=kill+shot+mod+apkPDF link annotation
    • 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_off0000d016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD016 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e828.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE828 17620 bytes
SHA-256: 2217deedb162454ecbf52400b5fefeacba253a4a06464503c2a4d88be0a1f6fb
font_02_sfnt_off000115e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115E0 10404 bytes
SHA-256: f91f06dfc5a22b2a25b255246f231b108ee115aa41d947196c5bbadc5135b011