Malicious PDF — malware analysis report

Static analysis result for SHA-256 37162762aeb2ee25…

MALICIOUS

PDF

76.1 KB Created: 2021-09-19 13:20:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 935ecc43b86c77c3f2f347cf1051956b SHA-1: 0c91e1edc8a114d760be3162ebaf9bb77d12a86e SHA-256: 37162762aeb2ee254d29bbf84f68cde24264f7d790460f5a4f3cdb14213ae1b5
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics indicate the document functions as a link farm, with numerous URLs pointing to potentially compromised or disposable hosting. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings supports this, suggesting an attempt to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://aaronandanthony.com/userfiles/files/52840111528.pdf In PDF document text
    • http://vvk-wiedermann.at/userfiles/file/50893223032.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/85323014127.pdfIn PDF document text
    • http://turatabor.hu/media/daxezijevaxazebibo.pdfIn PDF document text
    • https://www.sterlingsez.com/ckfinder/userfiles/files/60708682939.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/161326b0a45520---bikapedatizu.pdfIn PDF document text
    • http://longarmquiltingacadamy.com/fckeditor/userfiles/file/bukedoz.pdfIn PDF document text
    • https://5of7edwardstreet.com/assets/media/files/sepedijorofadapovu.pdfIn PDF document text
    • http://www.vishalsahni.com/public/ckfinder/userfiles/files/nujakuredorugagisu.pdfIn PDF document text
    • http://podlahyadvere.sk/editor_uploads/system/files/kagitovubeke.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/45049487994.pdfIn PDF document text
    • https://nomaquito-travel.com/editor-images/punopubelisotoz.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/zudutukisaroneta.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16141174f9e9a1---gesujakegokezitiwemij.pdfIn PDF document text
    • http://knowleangling.co.uk/ckfinder/userfiles/files/pixupivekibeborawamirexe.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/kuzutalowa.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/fb591c9df5fa00bce655fadfe14f38be/gokazovudo.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7c3266ed8---60492278167.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/55669054824.pdfIn PDF document text
    • http://myslizdrave.com/soubory/15163753954.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/51504762985.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/sewomusoterofivunabom.pdfIn PDF document text
    • http://usarsenal.it/userfiles/files/85056232148.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/vunekolijedunuz.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/pimazuwisotomurozafak.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=phone+stopped+receiving+textsPDF 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_off0000c744.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC744 10752 bytes
SHA-256: 9f6ec28a54e1973a0023518cbb507a99f8534826e160598b9f2fada9133dee5a
font_01_sfnt_off0000dfc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC2 16560 bytes
SHA-256: 30c7bd35dde2ab1b727dcf2ac65e949b047570186a2d7782afcd2d176715d1ba
font_02_sfnt_off00010ad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1