Malicious PDF — malware analysis report

Static analysis result for SHA-256 9da1657279d81341…

MALICIOUS

PDF

81.8 KB Created: 2021-09-17 02:07:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c38e37694a3232e17624a791b4f626c5 SHA-1: d31a57866b9d9654a01d2f5c232cf950ef30007b SHA-256: 9da1657279d8134114bad047e13c70a7348e3bede4298fbbabc203b1258daeac
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, with a critical detection score. The heuristic analysis indicates it's a link farm PDF designed to host other malicious PDFs, and specifically mentions a callback phishing lure where the document prompts the user to call a phone number. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content or initiate a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://stl-hk.net/userfiles/susepogumurotozedawo.pdf In PDF document text
    • http://adbrf.com/files/fckeditor/file/127831419613cc4d9a2911.pdfIn PDF document text
    • http://mudrkanuch.sk/editor_uploads/system/files/luwakepovikavus.pdfIn PDF document text
    • http://lagrupacio.cat/file/wipivebixilasatudub.pdfIn PDF document text
    • http://daiichihousing.net/uploads/news_file/14595719350.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/94630871647.pdfIn PDF document text
    • http://jvcc.cn/ckfinder/userfiles/files/21091516555182792235vgx.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/batodevaregewow.pdfIn PDF document text
    • https://cmoretv.com/userfiles/99599893267.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/70082498419.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/53516636979.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/fowigurukonuzevenupi.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/wadezututigotugubeveluda.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/11654579249.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/16132c14f9f3a6---juminosewolejobif.pdfIn PDF document text
    • http://encino.ilovepokebar.com/uploads/files/bokokinijibitegemejuma.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/fukudolefoxotojenapolopes.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/sivutid.pdfIn PDF document text
    • http://devison-matras.com/upload/file/linogu.pdfIn PDF document text
    • http://zlatartopalovic.rs/files/12713990069.pdfIn PDF document text
    • http://meetburgerusa.com/uploads/files/83887001259.pdfIn PDF document text
    • https://webornate.com/viking1/uploads/files/66698169458.pdfIn PDF document text
    • http://skazka76.ru/pic/userfile/rasoma.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/roxerinan.pdfIn PDF document text
    • https://wanna-drive.nl/files/File/98749852305.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=c%2B%2B+11+14+17+20PDF 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_off0000ddb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB6 18592 bytes
SHA-256: e36ba595e2e73d08a1b1691928e99392da881ea1733579587bd88d99b76549ef
font_01_sfnt_off00010d8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125A4 9532 bytes
SHA-256: 1f97b8e9d7483c9d79a6b820497d1adbb827302f18973551f04853c26b399a9f