Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b66fddaa99158ac…

MALICIOUS

PDF

94.6 KB Created: 2021-09-03 03:44:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b0624a014bdde4e5338a94e114e104a4 SHA-1: e04c70031fc37aed419cda64f0f84364d06c22ee SHA-256: 4b66fddaa99158ac7a3aa2912085722639f893071b33264bda142fa59f181b00
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to lure users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://beloezoloto.ru/userfiles/file/60000172.pdf In PDF document text
    • http://riggi.ru/userfiles/file/xawurafisopafaji.pdfIn PDF document text
    • http://njuhome.pl/ckfinder/userfiles/files/47973981499.pdfIn PDF document text
    • https://denizlihorozu.com/resimler/files/48079442456.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/83777185991.pdfIn PDF document text
    • http://m-camper.ru/ckfinder/userfiles/files/95597662934.pdfIn PDF document text
    • https://efnnma.org/files/file/21277556536.pdfIn PDF document text
    • https://llsindia.in/FCKeditor/file/lesalowuzibenupitizolol.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160adf30ac7d4c---lofowisexoxoxavovokoxe.pdfIn PDF document text
    • https://barcelona-health.com/files/galeria/files/67978804876.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/89rj2o78ob1kerslednpl22aa7/67020122586.pdfIn PDF document text
    • http://mtsp.by/userfiles/files/28171480204.pdfIn PDF document text
    • http://eventclub.pl/userfiles/file/radugezaxosatopumi.pdfIn PDF document text
    • https://baohohoanglong.com/userfiles/file/46401512312.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/rajqdsqq8df4g28a860o09csj8/zujow.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/vuzepugit.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ki2oqkdeug8vjioh59djbtb017/latemolakoze.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/lutivon.pdfIn PDF document text
    • http://chatfieldfarms101.com/userimages/38832214104.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/91556f7f0d85d9eeaf917bfc1689748b/67297409983.pdfIn PDF document text
    • http://liveranigioielli.it/userfiles/files/93153542857.pdfIn PDF document text
    • https://idea-web.ro/app/webroot/files/userfiles/files/nativuza.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdc0f5526a1---xosufo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=r%C3%A1pido+e+devagar+duas+formas+de+pensar+pdf+gratisPDF 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_off0001057f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057F 11184 bytes
SHA-256: 8ec11ba3969e3975f40f092a1c724688d982dc4945ad1d2a756917d154ca2ef8
font_01_sfnt_off00011f15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F15 20272 bytes
SHA-256: 16c2055e5c4fd89a50dbc3436e3993e461226feb90ee534d8c136f57e40d6f30
font_02_sfnt_off00015185.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15185 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1