Malicious PDF — malware analysis report

Static analysis result for SHA-256 823bb481ce72a91d…

MALICIOUS

PDF

80.6 KB Created: 2021-09-18 17:52:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: aa60e63cc87d2ad92b05007f63b257ae SHA-1: c3e8975c1baa1acd819cffbc652fa7a558aa6adc SHA-256: 823bb481ce72a91d4997bcb62c90acb63cc880425f98a56e3fd651264c6b3e0b
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to disposable domains, forming a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to manipulate search engine results or distribute further malicious content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://biometria.pl/photos_fck/file/sofavakamemamutibilig.pdf In PDF document text
    • http://puginternational.com/ckfinder/userfiles/files/korujojasawude.pdfIn PDF document text
    • http://insureavisitor.com/userfiles/file/puxawefinawel.pdfIn PDF document text
    • http://kawana.tech/userfiles/file/gunifemobasekepu.pdfIn PDF document text
    • http://kavernoklub.com/campannas/file/98805248218.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/fagugulilot.pdfIn PDF document text
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210910004624.pdfIn PDF document text
    • http://duet-czluchow.pl/userfiles/file/kawajoxosasuvu.pdfIn PDF document text
    • https://sooryasales.com/uploads/file/surejujibaleweg.pdfIn PDF document text
    • https://taumed.kz/upload/2021/09files/210917070335396013v7prx.pdfIn PDF document text
    • https://studioconcept-stand.com/fck_userfiles/file/pomipodaxoramotoba.pdfIn PDF document text
    • https://promaxsuspension.com/csmimage/file/wipaxesonutalaji.pdfIn PDF document text
    • http://thanglong.vn-greenenergy.com/ckfinder/userfiles/files/23388054971.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/abe9de6dd012f82cbe560b45aab81cce/nijozewota.pdfIn PDF document text
    • http://euroear.eu/ckfinder/userfiles/files/38501309844.pdfIn PDF document text
    • http://loaamtran.com/files/usersfiles/files/labaxef.pdfIn PDF document text
    • http://jilienjrubin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/30058638945.pdfIn PDF document text
    • http://unstitchedfootwear.net/files/file/botafexowevenula.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/fokukawalatejuwega.pdfIn PDF document text
    • http://sourceit.ke/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/16740860902.pdfIn PDF document text
    • http://coconut.hu/userfiles/file/rupakavisudefotelowox.pdfIn PDF document text
    • https://cukimentescukraszda.hu/files/files/poxuguk.pdfIn PDF document text
    • http://email-database.info/userfiles/file/fivitujebin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=catholic+bible+pdfPDF 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_off0000d7b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B2 17736 bytes
SHA-256: def8c9ca398ba33d45cebc2f99d249ed133b8cde88279032e94d44ae563e129f
font_01_sfnt_off000104f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F6 10516 bytes
SHA-256: 2c8b76c57db0a42ffb44d80c840720aa1ab35c395305aae4bb269ed326ce2012
font_02_sfnt_off00011ccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1