Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd510cd3ae89cb69…

MALICIOUS

PDF

71.7 KB Created: 2021-09-30 16:14:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b3686f1a165a62fed58fcf6dd8387c79 SHA-1: 1dbfd1a099938a90fde19d1b0c7bfc12bff7a2d3 SHA-256: bd510cd3ae89cb6963c46a148d491d17802b45bc858ac32aaa63ae9a7ca1bc29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, presenting numerous URLs that point to external websites. Several of these URLs are hosted on compromised WordPress sites or disposable domains, suggesting an attempt to lure users to potentially malicious content or phishing pages. The PDF's structure and the nature of the embedded links strongly suggest it is used for initial access via phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • 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.
  • 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://crewmak.ru/uplcv?utm_term=crop+pdf+pages+in+half PDF link annotation
    • http://kammatrans.com/userfiles/files/43778767478.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109191212127040.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614363e8d145b---29607182110.pdfIn PDF document text
    • http://manhtreminhduc.com/webroot/img/files/21367497327.pdfIn PDF document text
    • http://conganbacgiang.vn/app/webroot/uploads/files/zirakemajezapuvevuwenuj.pdfIn PDF document text
    • http://bugskin.org/userfiles/file/47486290286.pdfIn PDF document text
    • https://hoangmailogistics.com/asset/site/files/nowanevig.pdfIn PDF document text
    • https://quangcaowebsite.xemlaco.com/uploads/files/vegosemavev.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/lt2hjcdqfh4dgppjf434uptov5/76712989966.pdfIn PDF document text
    • http://wienbildarchiv.com/upload_files/files/78759642662.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/katalodese.pdfIn PDF document text
    • http://anael.fr/fckeditor/userfiles/file/vuluwenakexupibok.pdfIn PDF document text
    • https://cihangirhotel.com/upload/ckfinder/files/tatojiviloferulekawojuke.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/c60395ea95d4030f53b3a484dd72f5ad/mevujo.pdfIn PDF document text
    • http://oris-am.com/editor_up/wuwoxukigisib.pdfIn PDF document text
    • http://ingatlantv.tv/userfiles/files/rapifoferedejizeketo.pdfIn PDF document text
    • http://novichiha.ru/pic/file/mokuwubad.pdfIn PDF document text
    • http://ls12368.com/userfiles/file/pesilujemewewimolifusina.pdfIn PDF document text
    • https://kemxoi.vn/app/webroot/files/images/pages/files/riwipenexuko.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/fawovelegosoruwomasurevu.pdfIn PDF document text
    • http://bmfjhjk.friend-match.com/upload/files/9824125434.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/1cae3ed307e5353c95d62878ce8e5295/witedebumen.pdfIn PDF document text
    • 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_off0000b416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB416 17376 bytes
SHA-256: c83ea2f5d861eff751ee875338d1766f096bfffdece8937198b052c116451b84
font_01_sfnt_off0000e0d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f8e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E8 10712 bytes
SHA-256: 768d8f3b0165640d4e9e733f260e6970d5924edc841c83e5ee90ff59ee9c553e