Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b4a23bd59c8801…

MALICIOUS

PDF

78.2 KB Created: 2021-08-10 23:49:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: 8a5e9a40e699d5ee76909f43b8ef5de4 SHA-1: a07c84376a9adcba6d4df6548506c4cc97549211 SHA-256: a4b4a23bd59c8801191f5f90fb7cbbb1cdd1adbf05ce536059cf52586abdf7a4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/9d12e9d7edc953c48992a27ede85b3b8/37046551021.pdf In PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1700c26f0---24956107507.pdfIn PDF document text
    • http://air-ned.com/uploads/files/gobifiwifakatep.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f32c8274dd---dunetusikosuz.pdfIn PDF document text
    • http://healthywithhart.com/res/file/bivalilodemuzugenefixa.pdfIn PDF document text
    • http://driscollandgibson.com/images/edit_images/file/patekekipitomudepanux.pdfIn PDF document text
    • https://vivekanandbawwa.com/userfiles/file/28945470831.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/39712347201.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/danupupukomub.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606c98160e69b---totifeso.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d24453815b9---tenaserakakanav.pdfIn PDF document text
    • http://lawngo.net/fckfiles/puxelukawuloxus.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/xojapijimujuzoni.pdfIn PDF document text
    • https://machinex-machines.com/UserFiles/File/71575903052.pdfIn PDF document text
    • https://felix-schulze.biz/wp-content/plugins/super-forms/uploads/php/files/s1gl1mbl2h76dbjertcile8u7n/narazewevigevam.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/9rp49k7fshag76ssej8okbl920/kezapaduwofa.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/xonusapajupewigu.pdfIn PDF document text
    • http://thebrownbag.vn/upload/files/75357564760.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/weresefigepe.pdfIn PDF document text
    • http://bracyfamilyreunion.com/clients/c/c2/c2db1a97f769835965582c74015c7782/File/27786855635.pdfIn PDF document text
    • https://sikanderajam.com/Robinson/ckfinder/userfiles/files/70912723275.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095e6f4e734f---tanotowokitoso.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/uoumguqjbnr075g7kggfvrd4p0/73213422188.pdfIn PDF document text
    • https://pointsourcegroup.com/wp-content/plugins/super-forms/uploads/php/files/f1164319a20001a8467f632c5b7ab267/winakuxidetunona.pdfIn PDF document text
    • https://bruceleevideos.org/images/file/diritovulonivune.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/72c4ce147807c6da96fd54d8c475d5f1/fiwukejoradezupudutovuda.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=principles+of+statutory+interpretation+gp+singh+pdfPDF 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_off0000cd6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD6B 16348 bytes
SHA-256: fb1125c82ef9f29458cc5bbc2e05bef13a697c942e3c0cdd0eddb8bd78da2f7d
font_01_sfnt_off0000f7fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7FC 11116 bytes
SHA-256: d5ee3c5f98ece2347316f6d92fc66221b61b7d974f6c1df18e017b0cbc3ce42d
font_02_sfnt_off000111aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1