Malicious PDF — malware analysis report

Static analysis result for SHA-256 536077d02db9b9b8…

MALICIOUS

PDF

81.1 KB Created: 2021-09-11 16:38:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: cbf4de5cd3cdb27316e8b31a84f15cd6 SHA-1: c1a1219f60bdabe6302fe9a0bcdbce379a7c5ecb SHA-256: 536077d02db9b9b8b6f68523613dcdc500a479a0e778e1aafd83a1bb4bf2042e
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document contains a link farm, with several URLs pointing to potentially compromised CMS uploads or disposable hosting. The presence of a 'new job acceptance letter' UTM term suggests a social engineering lure to trick users into clicking these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://goforthegreengolfpools.com/userfiles/file/sezumevisosejudula.pdf In PDF document text
    • https://cooperspick.com/files/votosaf.pdfIn PDF document text
    • http://knupress.com/pds/editor/file/zulibijabezudawoturon.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/21020032001.pdfIn PDF document text
    • https://maxtarget.by/ckfinder/userfiles/files/37089316813.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/rifusu.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/bigavipilunakasezasiri.pdfIn PDF document text
    • https://firsatpin.com/calisma2/files/uploads/gapibexululo.pdfIn PDF document text
    • https://khoahoc.timviec365.com/picturesfiles/kozokebaduw.pdfIn PDF document text
    • http://luxlustry.ru/img/upload/52372401507.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/pijuf.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/14028943867.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613178630ebff---piridoramofigerusigitod.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/86214147545.pdfIn PDF document text
    • http://podolsk-kondicionery.ru/upload_picture/file/jiwagavunuke.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/77624103601.pdfIn PDF document text
    • http://ibrahimabuomira.com/ckeditor/ckfinder/userfiles/files/25105783201.pdfIn PDF document text
    • https://kubermatkaplay.com/ckfinder/userfiles/files/79956385580.pdfIn PDF document text
    • https://newsru.md/upload/userfiles/files/xufijonime.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16138bd12b79c4---86254457032.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/d0bebebf73bcd14e4aa34daa94fbd9c3/zobewabuni.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0dd49a069---44478764977.pdfIn PDF document text
    • http://clubsahdianagalati.ro/upload/editor/file/jegipudulewudixojazogif.pdfIn PDF document text
    • https://toliveinchristjesus.ceosale.catholic.edu.au/application/third_party/ckfinder/userfiles/files/76492339117.pdfIn PDF document text
    • http://nhungbaithuocnam.com/img-tvdl/files/neden.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/1416027921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=new+job+acceptance+letterPDF 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_off0000daea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAEA 10440 bytes
SHA-256: 5ea9a019f42d7d232e14a4046b8b325ddbe48eb7bdd79320967c301e842a0504
font_01_sfnt_off0000f292.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF292 17008 bytes
SHA-256: 52791d5f2cdb8705f03521095efa1a79d4ef7580129e9cd2991594247631253e
font_02_sfnt_off00011e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1