Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51c4d43895db7cc…

MALICIOUS

PDF

71.6 KB Created: 2021-09-24 22:56:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c8cece8c748edde6de5e7db127fde9d2 SHA-1: 82df6df99be2ae628ad2aefb2e26a772db345cd7 SHA-256: a51c4d43895db7cc9574dbc56d016c784b4acd6a58fabd848e611216e20c31a4
176 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://pixomot.ru/uplcv?utm_term=singham+2011+full+movie+free+download+480p PDF link annotation
    • https://limblength-sldf.com/userfiles/file/satakedumatonus.pdfIn PDF document text
    • https://chinese-wall.tw/upload/files/tuxoronimogagetesul.pdfIn PDF document text
    • https://panegovernance.com/ourprojects/chowki/UserFiles/file/48429273628.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/47271700639.pdfIn PDF document text
    • http://savoie-outils-coupants.com/ckfinder/userfiles/files/petuxami.pdfIn PDF document text
    • http://lt101shop.com/userfiles/files/9813403708.pdfIn PDF document text
    • http://affectif.ro/data/Image/file/44129027143.pdfIn PDF document text
    • http://atomleasing.ru/media/File/7526903108.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8ee9a28f2---76139586499.pdfIn PDF document text
    • https://centaur.vri.cz/docs/files/86158796623.pdfIn PDF document text
    • http://buren-kompanie.de/userfiles/files/5840768601.pdfIn PDF document text
    • http://efuturesthai.com/uploads/file/1053484562.pdfIn PDF document text
    • http://xn--spreewaldpension-lbben-9lc.de/meineBilderAlbertGrundschule/file/vixejoreb.pdfIn PDF document text
    • http://aryajob.com/user_upload/file/2098607526.pdfIn PDF document text
    • https://actionsporting.com/userfiles/files/toxogutaninaripoba.pdfIn PDF document text
    • http://buyyoutubesubscribers.com/ci/userfiles/files/xulaligel.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613dbad2a3920---bobonuvudim.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021091021145680554.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///20210914175617_1054596774.pdfIn PDF document text
    • http://esrafisek.com/images_upload/files/fevimigidusawijixelefek.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/zewif.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613a89860fb06---74905259834.pdfIn PDF document text
    • http://busto-wl.gattinonimondodivacanze.it/themes/userfiles/files/36384680073.pdfIn PDF document text
    • https://strongpointmarketing.net/userfiles/file/bonovipujidijaxel.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_off0000b2e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000caf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAF7 11588 bytes
SHA-256: 8f5c93d37db8390cec60f31152191d7e98bfa1e67c6d460948ffa6e342257958
font_02_sfnt_off0000e63f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE63F 16748 bytes
SHA-256: 5c960bfbdd7313ec6c7663c6835ec71e31325ed0201ea348ed56d6e02a4f4431