Malicious PDF — malware analysis report

Static analysis result for SHA-256 1e4a1877844d465f…

MALICIOUS

PDF

73.9 KB Created: 2021-09-08 19:14:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4fd4b8995e3d305681450ee8ed643eae SHA-1: afc4db38ee60418403dad0ef05cb9120116233d9 SHA-256: 1e4a1877844d465f223361c2048f735c97f6fc7815036c6c4b4df099e86e228e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URIs, many pointing to disposable domains and configured as a link farm, suggests a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains metadata from wkhtmltopdf, implying it was generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://maekalocal.com/Maeka/UserFiles/File/62521437750.pdf In PDF document text
    • https://instalacje-elektryczne.net/ckfinder/userfiles/files/66876934750.pdfIn PDF document text
    • http://sanruou.com/app/webroot/uploads/files/15789138225.pdfIn PDF document text
    • http://aqbnb.com/uploadfile/file/33126287110.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/59517472718.pdfIn PDF document text
    • http://tingchucontrol.com/Uploadfiles/files/37721094898.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/28611763999.pdfIn PDF document text
    • http://steakpluspizza.us/userfiles/file/72961462969.pdfIn PDF document text
    • http://stl-hk.net/userfiles/pulatu.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/zawopemivelikotupino.pdfIn PDF document text
    • http://kurier48.pl/files/userfiles/file/xejoduxurop.pdfIn PDF document text
    • http://www.vnos.vn/app/webroot/uploads/files/bafatojutalivuletuf.pdfIn PDF document text
    • http://dtyxbpzx.com/filespath/files/20210906051045.pdfIn PDF document text
    • http://nepalbestcargo.com/userfiles/file/vebepajiwegamosezag.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/2328730498.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612edcf7e6048---46550931308.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93393254673.pdfIn PDF document text
    • http://naplesredeals.com/userfiles/files/kulefojufegatenozediruwi.pdfIn PDF document text
    • http://the-bom.kr/upfile/files/rulige.pdfIn PDF document text
    • http://weldingplaza.com/files/file/velubobetomatun.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/96070526295.pdfIn PDF document text
    • http://ortopediaszombathely.hu/editor_up/lanerugamaguvofigav.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/dtj81fp2acaa5qinp4c0h5ggde/43817151533.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=convertire+pdf+in+word+modificabile+online+freePDF 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_off0000bcec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCEC 16796 bytes
SHA-256: 82ef04e963441be13b44cd62a19d2301d2e38d53fa32cb88f510a2118f9352d9
font_01_sfnt_off0000e8b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B0 10936 bytes
SHA-256: 93eb575945a3ae52e2ac3434473b9349d2c926c4e4f3531e436cf73cabada1b1
font_02_sfnt_off000101e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1