Malicious PDF — malware analysis report

Static analysis result for SHA-256 21115a1ff40229ec…

MALICIOUS

PDF

82.0 KB Created: 2021-09-22 20:48:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 207ba540bef8669d7deb952bca4a4a06 SHA-1: e9d8a3c4bd574f740e1c3ea1ecf2308543e386a1 SHA-256: 21115a1ff40229ecd56ef6e6a4ea9dee9378c87d7648c37017cbb3bde97b4ffe
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous disposable domains and UTM parameters suggests an attempt to obscure the true destination and purpose, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://crewmak.ru/uplcv?utm_term=how+do+emojis+look+on+different+phones PDF link annotation
    • http://mamaskitchenorder.com/uploads/files/jiwojejolefiwet.pdfIn PDF document text
    • http://www.abcklima.hu/data/editorfile/27525042836.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b031b2c465---73176462168.pdfIn PDF document text
    • http://geluidsadviesnederland.nl/ckfinder/userfiles/files/bixebuxogumunavod.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/3022990233.pdfIn PDF document text
    • http://stolizstekla.ru/userfiles/file/feluxopatasofij.pdfIn PDF document text
    • http://mcserpenti.com/userfiles/file/53307165984.pdfIn PDF document text
    • http://baoveantam.info/upload/files/wusazemolozawedadolejetu.pdfIn PDF document text
    • http://sage-chem.com/image/files/20210911_074646.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/kuredi.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/d33467c51312a6bc24d6824fd40a7a4f/31841712621.pdfIn PDF document text
    • http://music-summer-courses.eu/upload/files/kotaxofoxenilalonal.pdfIn PDF document text
    • https://gulfb2b.com/userfiles/file/16730537618.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/tujamuke.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/0293cbe2fa154c45c6610dda2d6b0121/pedabiwexizawen.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/nutuxegebowa.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/1951566548.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/54022261246.pdfIn PDF document text
    • https://episcopiaoradiei.ro/files/tulitasiz.pdfIn PDF document text
    • https://cfi-registration.org/buzzboxgift/img/userfiles/files/83609988937.pdfIn PDF document text
    • http://irpuyesh.com/cache/fck_files/file/vanajaso.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161339fa49304e---25733247249.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16131c1dde7864---79579557929.pdfIn PDF document text
    • http://tvkinter.com/file_media/file_image/file/96481295368.pdfIn PDF document text
    • 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_off0000dad8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAD8 10900 bytes
SHA-256: af9bcc046ad0d8e4e050eb9a601bd40ed26f368933eb2d5953d53238b1bdd3c3
font_01_sfnt_off0000f3c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C0 18220 bytes
SHA-256: b07feac65730e2538a8fdcce2431efc7e97eb664c1e2909ab504c4cb58f21945
font_02_sfnt_off000121c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1