Malicious PDF — malware analysis report

Static analysis result for SHA-256 83ea7537cd99ae5e…

MALICIOUS

PDF

80.8 KB Created: 2021-09-24 04:17:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a1d6d8c19308066fb25448dc96f4ca82 SHA-1: 85db06f058fadc5aa92f43992b42f165b960e65f SHA-256: 83ea7537cd99ae5e43dbb4f281c5b96c27297c88ee74d2303a61beb23c39f12d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, with many pointing to potentially compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. While no scripts were directly extracted, the PDF structure and embedded links suggest an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://sibconsulting.com/contents/files/276345734.pdf In PDF document text
    • http://khangvietdn.com/uploads/file/55373804061.pdfIn PDF document text
    • http://sun-apartments.pl/data/pages/nonusawenawibitezoved.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/supudogigezudi.pdfIn PDF document text
    • https://moiatakashta.com/userfiles/file/77514995040.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/wuweveteja.pdfIn PDF document text
    • http://ozdoby-betonowe21.pl/Upload/file/tufozekikesakoja.pdfIn PDF document text
    • http://savytrading.com/userfiles/file/ruvezele.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/jijopususurojumagutejo.pdfIn PDF document text
    • http://alvit-bk.ru/userfiles/file/sirowitulenenugukimo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138eb3ea9730---monepelawovute.pdfIn PDF document text
    • https://ms2oke.com/contents/files/lererorefupifumid.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139f8ecf3ac8---5428926079.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/161406831664ec---wikupobutizasevenuf.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/79377506536.pdfIn PDF document text
    • http://dgjst.com/upfile/file/81319128610.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/c8c73ec7293953f3d47439171c475c44/xarasabejejofabimivuma.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/161469f7f995ab---kokofajin.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613083689e42e---wefimukeseladajige.pdfIn PDF document text
    • http://vatlieubaooncachnhiet.com/userfiles/file/72933714398.pdfIn PDF document text
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/91210628471.pdfIn PDF document text
    • http://rtm-plus.ru/ckfinder/userfiles/files/93701665189.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/widemikokotepalu.pdfIn PDF document text
    • https://plentis.eu/ckfinder/userfiles/files/judew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=imo+beta+2019+apk+downloadPDF 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_off0000d5e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E0 10924 bytes
SHA-256: b625370d4ed859cc67f0bbb8ce7f4bf8e4b6cda152e4554a136607b8431e1292
font_01_sfnt_off0000ef13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010725.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10725 17904 bytes
SHA-256: ffcdf075a52a5c0e4e6567c5d19bb98d3ce04681436dfd464172379f56d986a4