Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf4556a408fb1b85…

MALICIOUS

PDF

70.1 KB Created: 2021-09-30 17:23:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9b676b9fd1c25071bf8eaa0e6b1836b2 SHA-1: a58a2a29c3a05dc0c37a2ddb7ba9179346e0e5d2 SHA-256: cf4556a408fb1b85b7c32268578a26338ae45e041b94500d4e233f21be9703bd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to various unknown domains, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the presence of embedded URLs and the overall structure point towards a malicious document designed to exploit users through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://dienlanhlongan.com/upload/files/koleluleri.pdf In PDF document text
    • http://inventory-acepipe.com/images/uploads/files/29465342002.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/cnqatiai74baj6q7degsiu74am/10735489183.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/vijazegibozegenamazepel.pdfIn PDF document text
    • https://samoinstitute.mn/uploads/assets/file/29647231513.pdfIn PDF document text
    • http://a-pluset.com/userfiles/47860796081.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/29070724984.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/19232083001.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/10114602678.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/mubopitifixesapad.pdfIn PDF document text
    • http://xn--k1akb4c.xn--p1ai/userfiles/file/bubupudisudofaki.pdfIn PDF document text
    • https://greenbins.ca/ckfinder/userfiles/files/73801812849.pdfIn PDF document text
    • http://golden-candies.ru/webroot/files/files/21620677354.pdfIn PDF document text
    • http://onishi-kyosendo.jp/archive/bajiwaba.pdfIn PDF document text
    • https://rsebolivia.org/userfiles/file/90989279138.pdfIn PDF document text
    • https://sklep-pinokio.pl/web/uploads/files/71048405742.pdfIn PDF document text
    • http://fundacjahfg.pl/upload/file/71602099814.pdfIn PDF document text
    • http://szjglaw.com/uploadfile/file/2021091800573073499.pdfIn PDF document text
    • http://deliver.cueicha.com/assets/upload/files/dilalalevaluselajik.pdfIn PDF document text
    • http://spartapr.com/images/upload/file/niborusegupaxabinibus.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3357b0cc5---11746174133.pdfIn PDF document text
    • http://thibangoto.com/app/webroot/uploads/files/70152491176.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/sowivixibavamojadodolufe.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/13879419298.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=fireboy+and+watergirl+crystal+temple+frivPDF 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_off0000afdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFDB 11348 bytes
SHA-256: 2bdf04d53bf895fbd3acd164a6baa071fd7c7688d0d46f92a692627d8737c001
font_01_sfnt_off0000ca30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA30 15880 bytes
SHA-256: b7e4a5a86c1dfcd7da865cff4ad1716e0f0ecc52de48d0c55024331a22c852e6
font_02_sfnt_off0000f2cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1