Malicious PDF — malware analysis report

Static analysis result for SHA-256 357dc0ddf4a8685d…

MALICIOUS

PDF

85.1 KB Created: 2021-09-13 08:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 572caad13f65142c96a20149095dcbe8 SHA-1: b1a8290a5e39c4ed1504f4f1dbf5cb1775823196 SHA-256: 357dc0ddf4a8685d1f0a5ce658432286cc95f685f64a977007c0a717b316dc46
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate this PDF is malicious. It contains numerous external links, many pointing to disposable domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the final destination. While no scripts were explicitly extracted, the PDF structure and heuristics point towards an intent to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://ceramicasvillaflor.cl/UserFiles/File/golutaro.pdf In PDF document text
    • https://thefertilizerequipment.com/d/files/rejixupomefodojowum.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/7217195894.pdfIn PDF document text
    • https://cdmsig2.com/ckfinder/userfiles/files/wagusaxumimunolovi.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/kojixosonopomutaranoxudo.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/fapezelemil.pdfIn PDF document text
    • https://rendszergazda-cegeknek.hu/ckfinder/userfiles/files/mifumupovosaxedujibo.pdfIn PDF document text
    • http://aspbae.org/userfiles/file/9848342958.pdfIn PDF document text
    • http://moto-bike.pl/userfiles/file/kolezupegupuwaluxogi.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/xodeluziwupinoraxusejis.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3d8485dde---nujoxuvujidof.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/83800419834.pdfIn PDF document text
    • http://boracayg.com/FileData/ckfinder/files/20210904_12838C0EC417B450.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/pivogumetegesolawem.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/rofudifofejupadebo.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/3680497625.pdfIn PDF document text
    • http://hublihorse.com/uploads/userfiles/files/ganorabudoxaf.pdfIn PDF document text
    • https://etest.vn/app/webroot/uploads/files/mojofalewifef.pdfIn PDF document text
    • http://chekeeh.ir/basefile/chekeehir/files/bosafokinimezofun.pdfIn PDF document text
    • http://coytex.net/ckfinder/userfiles/files/xawakutijejipiz.pdfIn PDF document text
    • http://www.bc-arman.kz/ckfinder/userfiles/files/75030427871.pdfIn PDF document text
    • https://efnnma.org/files/file/80181621066.pdfIn PDF document text
    • http://wellnesszeewolde.nl/site/data/ws/files/76165084614.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=roadbook+app+androidPDF 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_off0000e928.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE928 18056 bytes
SHA-256: 17c8da01452d5a4511604231967ca6b65b04ce8a5674ddf9a4b58a59cb4ed9e6
font_01_sfnt_off00011807.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11807 10220 bytes
SHA-256: bf9e5a95fe506c25e05d83efb42020bdf3d4753f9f7231b0c8360f918407f9a5
font_02_sfnt_off00012ebd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EBD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1