Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f57856c3e1eb160…

MALICIOUS

PDF

77.8 KB Created: 2021-09-12 19:01:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cc30ce25d0743ecf7e89a1c2111b58c8 SHA-1: 78d663bbd0cb30f66bf59e03edb64dc950fa995c SHA-256: 5f57856c3e1eb160877b03968074aa4ef3c23f31d4cc056d0c5aa06242533d20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous PDF links on disposable hosting further supports a malicious intent, likely to distribute phishing content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://retrolondontees.com/userfiles/file/sazejefeveduvuneri.pdf In PDF document text
    • http://goldendazzle.com/upload/quangtri/files/gogatomilufajopa.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/netubamibavit.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/lunoxupud.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/powud.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3501dd3fa---nukusefesutubowavaviwewi.pdfIn PDF document text
    • http://intertermo.nl/userfiles/file/88568221982.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/887355f3e1cb90e0d1d6ebe4c635689e/molesonurosoka.pdfIn PDF document text
    • http://immobilieninvestors.com/userfiles/file/xemakozemidog.pdfIn PDF document text
    • http://xn----7sbqwxdbhblh2h.xn--p1ai/data/file/fifomufefokejiniju.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/59482961292.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/63941649859.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210911170156728.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/86116129175.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/xewexojabujagepefo.pdfIn PDF document text
    • http://imailbox.nl/images/uploadedimages/file/buvuweberudizizik.pdfIn PDF document text
    • http://orvosvalaszto.hu/uploads/files/15911890891.pdfIn PDF document text
    • http://susasoft.com/upload/userfiles/files/44459427091.pdfIn PDF document text
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/fadopomabezupalip.pdfIn PDF document text
    • https://spbmworld.com/anaeter_capital/siteadmin/userfiles/files/90140329278.pdfIn PDF document text
    • https://whitepalacegrill.com/userfiles/dunalibaxomukesokase.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130e11353a41---12234505485.pdfIn PDF document text
    • http://hoteldazegliotorino.com/userfiles/files/fukirirewobumiku.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/wirenubuganogogor.pdfIn PDF document text
    • http://chinatriage.com/ckfinder/userfiles/files/pasabexuwoxasefugaluni.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=friends+watch+online+with+russian+subtitlesPDF 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_off0000ca87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA87 17348 bytes
SHA-256: d2cb1689b878305c2dbf5d547f6aec7b7e331605000082127b4c0f3c7484b28b
font_01_sfnt_off0000f72e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72E 10772 bytes
SHA-256: e9e3a90829990c231c090093c20dd450cc8df159967b806140ca8a3f45d7a428
font_02_sfnt_off00010fee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1