Malicious PDF — malware analysis report

Static analysis result for SHA-256 231ecdf33f3a2ed6…

MALICIOUS

PDF

84.9 KB Created: 2021-10-07 13:17:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: fa1a2ae110ec38a84d4f7aeb73578e57 SHA-1: 697acb86716ae8722dc24fc834cad6dad90fd107 SHA-256: 231ecdf33f3a2ed6bf30b45458f2fa02a0c76e12ec410211769da3853480bc0e
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The sample was identified as malicious by ClamAV and an ML classifier, with high confidence. The 'SE_CLICKFIX' heuristic indicates the document likely instructs the user to press Win+R or paste a command into a terminal, a social engineering technique to bypass macro restrictions. The presence of numerous links, many pointing to PDF files on disposable hosting, suggests a link farm designed to host or redirect to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://folientastaturen.pl/_data/file/86372809959.pdf In PDF document text
    • http://prompol.com/media/file/24795094956.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__615DACCBC6611.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/76193957393.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/vuzidulamogi.pdfIn PDF document text
    • https://opsclown.it/ckfinder/userfiles/files/fizujuramibazeladuzo.pdfIn PDF document text
    • http://synergyproperty.com/images/files/21401670663.pdfIn PDF document text
    • https://quizai.com/uploads/files/20562865873.pdfIn PDF document text
    • http://gekon.net/userfiles/file/966111350.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///60521546964.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/zofaxigolegenadofijivog.pdfIn PDF document text
    • https://journeywithmypet.com/ckfinder/userfiles/files/8033329826.pdfIn PDF document text
    • http://net-marketing.hu/images/files/voxuwibiposag.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/gotukalovadebomubowoli.pdfIn PDF document text
    • https://icnj.net/ckeditor/ckfinder/userfiles/files/dudubalekigirej.pdfIn PDF document text
    • https://koratspring.com/upload/file/memewubenarumofudevejon.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b90e3ce59a---39769882443.pdfIn PDF document text
    • http://nuovartea.eu/userfiles/files/98047251337.pdfIn PDF document text
    • http://quranday.org/userfiles/file/xatazizadeladituronok.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/8546046010.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/savegorosinakexipube.pdfIn PDF document text
    • http://contua.org/userfiles/file/difizawojanil.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16159d7662a09a---jujaxodewuvadepawigiteref.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/jodagoxizadexulezaseje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=what+is+the+insert+key+on+a+keyboardPDF 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_off0000da71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA71 22520 bytes
SHA-256: 7fb3fe76e3b28763aa1b711ddeebb7e55b04856e562488c7ee9c371d5082dd5a
font_01_sfnt_off0001153a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1153A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012d51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D51 10640 bytes
SHA-256: 76fdb5a8f9c79ed352171b80ed38f5dbcd6ee66ea92bb1f78e19249334619e7f