Malicious PDF — malware analysis report

Static analysis result for SHA-256 38b0b739ff816834…

MALICIOUS

PDF

75.2 KB Created: 2021-09-27 03:56:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0535bd74d4f7be4686c77bf511af7f47 SHA-1: 4e872461dbd9caa7b0bccbf66bffdb227dd93924 SHA-256: 38b0b739ff816834e68cea54da49173644b27054002893354d792e6563e04d8b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed as a link farm on disposable hosting, with numerous distinct hosts pointing to PDF files. While no scripts were explicitly extracted, the nature of the link farm and the detection as a trojan suggest it likely contains embedded JavaScript or other mechanisms to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145d0a610653---75734381418.pdf In PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/79860109933.pdfIn PDF document text
    • https://raselapp.com/userfiles/file/kemubatadojukozazobozunex.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/vukafu.pdfIn PDF document text
    • http://taiwanglassgroup.cn/userfiles/file/gokasukawukuladeliwepivos.pdfIn PDF document text
    • https://kaemsp.org/upload/editor/file/xasepuxezowonud.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/74465174065.pdfIn PDF document text
    • https://nacituran.com/userfiles/file/fowazifofusuvenubelum.pdfIn PDF document text
    • http://hsaltsj.com/uploads/files/kolumotibuweretadexeg.pdfIn PDF document text
    • http://archidaldegan.eu/userfiles/files/lexanutepopopam.pdfIn PDF document text
    • http://insei.eu/userfiles/files/kabaxola.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161387c5997cf8---14453072520.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021091701260173499.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/vumetojexonobonufo.pdfIn PDF document text
    • http://phonphangschool.com/upload/files/51063060450.pdfIn PDF document text
    • https://chinese-wall.tw/upload/files/69860229855.pdfIn PDF document text
    • http://rpsbchamber.org/editorData/file/69959505822.pdfIn PDF document text
    • https://vendax.ro/files/file/mulim.pdfIn PDF document text
    • http://stillincontact.com/images/mails/file/73002559498.pdfIn PDF document text
    • http://tuvantindat.com/uploads/2021-09-07/images/files/nilabagadavew.pdfIn PDF document text
    • http://gr-chem.com/upload/files/gemexakel.pdfIn PDF document text
    • http://st-communications.com/ckfinder/userfiles/files/76153905375.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=galaxy+s3+live+wallpaperPDF 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_off0000bd3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD3D 19268 bytes
SHA-256: 7fee3967bd4c34647785bcf480f0d53e94428383e59584ce4237309172fdf3df
font_01_sfnt_off0000eeea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010701.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10701 10500 bytes
SHA-256: b9a03442fcbb6b1779cc0941b0823587d0b6bf6ca28e76a5d2f9d4810d1c4920