Malicious PDF — malware analysis report

Static analysis result for SHA-256 11dc4a883b9d6908…

MALICIOUS

PDF

83.5 KB Created: 2021-09-18 15:43:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: af5062e687f792c3be3ec41eb8a58329 SHA-1: c1eae61cfe61d879a6ef5ce599fc5d81229428f7 SHA-256: 11dc4a883b9d690894369a9f4cc1f7807aa01157e56e9fea35513e92feb7142f
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it is not intended for direct user interaction but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://kaptenhoki.net/contents/files/96785273372.pdf In PDF document text
    • http://gmicropilotes.com/uploads/files/47239990530.pdfIn PDF document text
    • http://shanghaicruiseparty.com/uploads/file/retesowujularapulufimude.pdfIn PDF document text
    • http://kondicionery-fryazino.ru/upload_picture/file/43240549333.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/vanedomuwize.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/52308409348.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/nobejudewuvegas.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/56644786074.pdfIn PDF document text
    • http://ymmicro.com/files/files/fuleletadanubuton.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/99598bf6faa15d2fdb68ffeea6ce25d2/pezibizewasikorapumobob.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/r2t0l9tfs7abufdoh1s3b2rb6p/16222374630.pdfIn PDF document text
    • http://autovoda.ru/upload/files/naburipivikeno.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/77618415678.pdfIn PDF document text
    • http://industrialdevices.in/uploads/bipulukokajupil.pdfIn PDF document text
    • http://bhk-aindling.de/userfiles/files/jumoj.pdfIn PDF document text
    • http://analhospital.net/file/files/80147376883.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f88f44b6e3---pizobakitapapijopukuweseg.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/83327510644.pdfIn PDF document text
    • https://rumputhijau.com/contents/files/51487488940.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/jaxewovenomozarizirisa.pdfIn PDF document text
    • http://uniquehotelsolutions.com/files/others/3205872829.pdfIn PDF document text
    • https://louvre.lv/res/wysiwyg/file/xatilivobonibiv.pdfIn PDF document text
    • https://srldirect.com/ckfinder/userfiles/files/41542746576.pdfIn PDF document text
    • http://purepassion.pl/userfiles/file/58381610549.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=online+football+streaming+websitesPDF 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_off0000e254.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE254 10808 bytes
SHA-256: f41fd83173142691ea3cd43aec50decdb2622675157f28c84e5041011f68cd3f
font_01_sfnt_off0000fb53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB53 17364 bytes
SHA-256: 562e1aab50420ce6ed6102f6dbc10d515939f1fa9f3d15554380d8c751eea09f
font_02_sfnt_off000127f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1