Malicious PDF — malware analysis report

Static analysis result for SHA-256 c41ce5770bddfabb…

MALICIOUS

PDF

79.2 KB Created: 2021-09-18 09:58:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6b7e49726a9142fc3359b77182a130f8 SHA-1: 35e93ffab9b43d0de60e37b47e2227338b7aa63e SHA-256: c41ce5770bddfabb83733cacf3faaba375ca7cddc2a7d6850e20e2b3b9539e78
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. It contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. While no scripts were explicitly extracted, the PDF structure and embedded links strongly suggest it is used as a lure to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://mmbc.cz/_data/user_files/file/93149165888.pdf In PDF document text
    • http://bluekeydigital.com/images/pic/file/56584329641.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/ludir.pdfIn PDF document text
    • http://podolsk-kondicionery.ru/upload_picture/file/fazedekunav.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/kimisodebalap.pdfIn PDF document text
    • http://hataylezzeti.com/resimler/files/96046328234.pdfIn PDF document text
    • https://helices-evra.com/userfiles/file/lixejaxusipi.pdfIn PDF document text
    • https://hojoairport.com/images/file/61924713661.pdfIn PDF document text
    • http://wwsm-us.com/files/file/6692632547.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f0c1dacf25b47815a23673448aad485d/9228031901.pdfIn PDF document text
    • http://bluekeydigital.com/images/pic/file/82723949224.pdfIn PDF document text
    • https://actaviaserica.org/board/file/files/jalapuxevepasixegitibip.pdfIn PDF document text
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/fafivigafonig.pdfIn PDF document text
    • https://laplacedesstores.com/upload/file/dejerekogowimejaralo.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/wivugezebedazudolimug.pdfIn PDF document text
    • https://sim2007.com/files/20634709050.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/dizet.pdfIn PDF document text
    • http://aid-calais.com/userfiles/file/29932360348.pdfIn PDF document text
    • http://safetruck.gr/images/file/16021052100.pdfIn PDF document text
    • http://qdjshg.com/files/file/64970665531.pdfIn PDF document text
    • https://majubesar.com/contents/files/78777150411.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/kowezusejivada.pdfIn PDF document text
    • https://mekongtransport.com/upload/userfiles/files/31337308626.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+set+password+to+turn+off+androidPDF 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_off0000ce88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE88 10624 bytes
SHA-256: b8cfb208eb7fbe0b03fa08f18f6916f8a2e2684c6857004ea093f73a6e3ffc12
font_01_sfnt_off0000e6fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6FC 18572 bytes
SHA-256: af9a5cc9bf3c50b37460402190d441eb44c02067f05e446ac22688a35be5acde
font_02_sfnt_off0001170d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1170D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1