Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1721056cc4db1aa…

MALICIOUS

PDF

87.6 KB Created: 2021-09-07 01:35:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: cdc092dcfa840e40ec6bc866bbdd2783 SHA-1: 0dd9dde003535ac1fdf2c49bd1f2035390e50aed SHA-256: b1721056cc4db1aa009847be280b242926f02fe5f6c9ef29304fa7726638622e
156 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. ClamAV and ML classifiers also flagged this file as malicious, specifically as a phishing trojan. No scripts were extracted, and the document body was unreadable binary data, suggesting the malicious functionality relies solely on the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://calmoinc.com/upload/editor/file/49753481070.pdf In PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16085decc5846b---nekepanowew.pdfIn PDF document text
    • http://limeitec.com/upfiles/editor/files/tububijejuzorasefosifotu.pdfIn PDF document text
    • https://stopserv.ru/files/file/1973947385.pdfIn PDF document text
    • https://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/e3c1b3e89ba719aa12e601eb7c89dbcf/36703579964.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/22316139931.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/de68cbf25988ded7fa205623fa075455/belit.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/a9678bb8059675a0e9c395ac99dff261/97176312184.pdfIn PDF document text
    • https://beyondpins.com/calisma2/files/uploads/xadikudozewumor.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2mkplksgpspkhs8fqadtui7tj0/wesamuzid.pdfIn PDF document text
    • https://fsbulletsandbrass.com/userfiles/files/molokonarusofijorozu.pdfIn PDF document text
    • http://pitafest.com/clients/1/13/1337b7689af00ddd847345d48bd720ff/File/23339579306.pdfIn PDF document text
    • http://vkts.se/userfiles/file/59419136670.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/04eb1b68f25529ba39b0d45c4ec9a28f/93055078823.pdfIn PDF document text
    • http://odessahighschool1970.com/clients/7/70/70263b1be1b93b62200e198143f59f20/File/18777655948.pdfIn PDF document text
    • http://vogiantinhmach.com/media/ftp/file/gigutezamo.pdfIn PDF document text
    • https://sunridgecorp.com/uploads//files/202108050945133565.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a99fc6221fc---lopivojabanodu.pdfIn PDF document text
    • https://gaziemirkentkonseyi.com/upload/files/31220813315.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ef12a4192---95327071313.pdfIn PDF document text
    • http://thegreenlegacykeepers.com/clients/e/e8/e8dc17949b7ef813e9937e453902477f/File/88186769514.pdfIn PDF document text
    • https://thepainter.asia/upload/files/poguloru.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/jetibuperuvakolopisefemak.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/lafulosib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=parts+of+speech+poem+pdfPDF 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_off0000f182.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF182 18000 bytes
SHA-256: 30b3745735d12b171f8c16eafd02af6c2c317067e1cb9cc131904d84fcc571a4
font_01_sfnt_off00011ff2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF2 10644 bytes
SHA-256: e96048ec22c29eeda1e14273327b036268239b39628f087ecee9152aeb81837b
font_02_sfnt_off0001385f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1385F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1