Malicious PDF — malware analysis report

Static analysis result for SHA-256 81869717ce6913ca…

MALICIOUS

PDF

77.7 KB Created: 2021-09-07 09:14:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2a204618c63eeb292bfcc7b952216fb5 SHA-1: 835f3283a80f498fdc3a16292f38361414bbfdc5 SHA-256: 81869717ce6913ca379dde588435fc116c0487d76f4647e5d64695b97f0037e1
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to various websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/deff6ad907e146c1a0f99857d5be277e/37818948654.pdf In PDF document text
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/lasubinupifeja.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c778c9d2e4---67273074904.pdfIn PDF document text
    • http://moyamoya.center/images/hand_uploaded/files/26682523270.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c37aed92e50---6180992601.pdfIn PDF document text
    • http://josephlillianmorrisfamily.com/clients/59960/File/tupisitik.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/j8afiedq461qsb68nkpa5fr3g8/kedoxajedekawon.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/11787231490.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/f530ce94f3ccb66c3ab4601501e203e6/nopevuzelalezotapagorut.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/jidonagetun.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd7ff9ec598---dabowegofolokepezepataf.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/pa3pplc2i9ujm656e8li6csf98/zojog.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ed2b389598e---pamirudavodafu.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/609f39974acaa5094acfc0781d4085c8/pazepijarogosumixewi.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/dejjls2bi6vfp4b6cqg9egc6m6/7037446631.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16207494677987.pdfIn PDF document text
    • http://laros.cz/UserFiles/file/65048190033.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/dumureputo.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/ad81893a5bcb88e19cde013b3179f494/6787301033.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/golavixa.pdfIn PDF document text
    • http://acmemask.com/upfiles/editor/files/nibinopumim.pdfIn PDF document text
    • https://www.scmsgroup.org/ckfinder/userfiles/files/94958386685.pdfIn PDF document text
    • https://lasanisports.com/files/jifopap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=exponential+growth+and+decay+worksheet+answer+key+algebra+1PDF 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_off0000c9ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C3 11360 bytes
SHA-256: f941fc49e42f714c03bce5b480ddcb572e9cad88a86e9c5fd04d1e214ae88925
font_02_sfnt_off0000fc25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC25 16980 bytes
SHA-256: 469a1168d34894ced3328d292b59b16b13005d82db3615fbded245b7b516c058