Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc556658061040d9…

MALICIOUS

PDF

77.5 KB Created: 2021-09-11 23:15:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 36beb0cc4f3dbeda5dfbf0a2bddb9b50 SHA-1: 2ffbb9b256ce320488f6ae70ddf851aecdd9c8b0 SHA-256: dc556658061040d9cc764e2012e8cea68e50ef88ad46f8969d6ef99ae6c038c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The embedded URLs and the nature of the link farm suggest an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://kamionosnyelvlecke.hu/userfiles/file/zosedo.pdf In PDF document text
    • http://nextgenship.net/upload/file/20210831163044993028.pdfIn PDF document text
    • https://abyway.lv/images/ck_images/files/tezumunej.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/52700704941.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134adf66b55a---pipafuzopinizotovomeloz.pdfIn PDF document text
    • https://duongthuy.net/userfiles/file/sujefesijupawanefiru.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/lemuvixavorivakijutiwago.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1631235632.pdfIn PDF document text
    • https://recrut.com/files/files/bodolurinoniz.pdfIn PDF document text
    • http://bonsite.nl/phpcmsys/file/38316810626.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/13918392792.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16131d0e8ed0a1---legidewidizujaroko.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613230a3c5362---15632772772.pdfIn PDF document text
    • https://bdprescription.com/ci/userfiles/files/kipagiseg.pdfIn PDF document text
    • https://factorysales.com/userfiles/files/diwedobinamabosovitab.pdfIn PDF document text
    • https://hurghadalife.net/userfiles/files/josuvomi.pdfIn PDF document text
    • http://satyavnetworks.com/fck_upload_images/file/kezigu.pdfIn PDF document text
    • http://phongthuyphatloc.com/luutru/files/juvowidedowom.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/pipusimaxupe.pdfIn PDF document text
    • http://spartaksedlec.cz/spartaksedlec/userfiles/file/652473829.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/57773471053.pdfIn PDF document text
    • http://spbmedaks.ru/sites/default/files/uploads/dawufora.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1612f54b4843c5---46461633857.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=what+is+pattern+lockPDF 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_off0000cce5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCE5 16736 bytes
SHA-256: 4350cf355679d3eb865c2a4909c465126de8e88150bc3e4cb212799276e11f09
font_01_sfnt_off0000f826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF826 10556 bytes
SHA-256: 157ac6c5af1e3d108c10b1829ae4a0cf56bc3733d41b7707187b874b185079ea
font_02_sfnt_off00011039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11039 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1