Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8aa3565f5482f0e…

MALICIOUS

PDF

84.6 KB Created: 2021-09-18 04:49:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 134d385ddc793ff1a5329255d23c5a1a SHA-1: 3769eeb83bac32df7d4ad7ed1eac59282b04766e SHA-256: c8aa3565f5482f0e79d30bc5812905e983b3ed13a45ec9a9616db47fc6d5f7da
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's used for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious workflow, likely involving the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/he2gmtt5t1a6qrvolutprct4h0/sezuzikubiberejavebanezo.pdf In PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eefce18e4b---baduvoxivakizukugewun.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614320c77f490---51111236724.pdfIn PDF document text
    • http://www.fuchingrading.com/upload/file/76027805732.pdfIn PDF document text
    • https://bvphcn.bdata.vn/upload/files/77618415678.pdfIn PDF document text
    • http://tamphuhiep.com/Images_upload/files/sujotewalonigajirupaxij.pdfIn PDF document text
    • http://sportservistocik.cz/UserFiles/File/pijeweme.pdfIn PDF document text
    • http://www.dawnrotaryclub.tw/UserFiles/files/xatoximawolugu.pdfIn PDF document text
    • https://halead.com/uploadfile/1631921373.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/zazeditalup.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/73020751626.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109150925335166.pdfIn PDF document text
    • https://olterus.com/contents/files/vuletusivodulipevese.pdfIn PDF document text
    • http://tencanpowder.com/d/files/57005163410.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021091804471373499.pdfIn PDF document text
    • https://markiza-trade.ru/admin/ckfinder/userfiles/files/foboxejozigipiwi.pdfIn PDF document text
    • http://kanizsakran.hu/userfiles/file/wivodiga.pdfIn PDF document text
    • https://sanidom.pl/img/file/fojuwidizopabefewemogama.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/4cb53fa823201c9b8f5a240f283ecc18/kavufewo.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/68322535719.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/xirozomitekesikuvolapuxo.pdfIn PDF document text
    • http://linklandhotels.com/upfile/editor/files/6521801040.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=kingsman+3+full+movie+download+filmyzillaPDF 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_off0000e5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fddc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDDC 11088 bytes
SHA-256: 4cdd1555909d5d93f7e1f460ec8ad586b77d713c75d46dbe186420cc9b1a0fc8
font_02_sfnt_off00011798.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11798 17256 bytes
SHA-256: a3ca9645d2bbd33e6bbb08cf32c3953c17f503fe80a4485c07663f14aeb9c5e3

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