Malicious PDF — malware analysis report

Static analysis result for SHA-256 137b66f42d7b18cc…

MALICIOUS

PDF

86.4 KB Created: 2021-07-03 03:18:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 7dd9e2f6cf67ea0a4b5ab1961003cdb5 SHA-1: 16ef5afd6c138f33b5018ca0a555de83d579a436 SHA-256: 137b66f42d7b18cc8d46ba4a16d6a1d8b80d459bfef77b1e9a8eecbe6062b1c0
196 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a phishing lure, specifically prompting the user to install a browser extension or update to view content. This is supported by the 'SE_BROWSER_INSTALL_LURE' heuristic. The presence of numerous links to PDF files hosted on various domains, some of which point to compromised CMS upload storage, further indicates a malicious intent to distribute further payloads or redirect users to malicious sites. While no scripts were directly extracted, the overall structure and heuristics suggest an attempt to exploit user trust for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://rdmsrl.it/userfiles/files/28601788189.pdf In PDF document text
    • http://www.pranabkumar.com/fckimages/file/12248928591.pdfIn PDF document text
    • http://tovicetour.com/FileData/ckfinder/files/20210615_06C32D73F4397108.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/dacjlvs42k8pkebh2kle3qdi45/54378261177.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160a8823c9aa37---5094497425.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16075287cef522---20497959185.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/pabukex.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/hso9iaij1hchj6b6irgb5rmoi4/xawasum.pdfIn PDF document text
    • http://costanzolegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zinoxilexapixabogemolapud.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/gj65egubbm8ufmeh6k4qk83ch3/ponigajaxuvujavidizuw.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/monuwuwifubetoxofaxob.pdfIn PDF document text
    • http://goldnumber.info/userfiles/file/falugajujomesomajor.pdfIn PDF document text
    • http://k1a.ru/images/files/file/visufusupada.pdfIn PDF document text
    • http://mega-gold.com/userfiles/files/xanojup.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/8oh1fdj0dnss8rmd1lf89ig730/tufegorirozegu.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/51440832768.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/fk0tdg0aeabij13831b8to6tq2/1110479615.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddfba29e19---datapofeloxowosoba.pdfIn PDF document text
    • https://sharadsangam.org/UserFilesTwo/file/figibubofu.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/52178988482.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/6cf0bd2620b9ef36a517504a2d5371b2/47406211610.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/2tni0u1sdacmjle9nmkrgtheci/majuzenedovalelokudenipi.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076a1d44eb7d---falawiluxebijusamupa.pdfIn PDF document text
    • http://csc0451.com/userfiles/file/20210610155204_igbp53.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.com/userfiles/file/batege.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=count+words+in+a+websitePDF 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_off0000ef81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF81 16900 bytes
SHA-256: 2312cfe95acdfeff5a3fbf0a0e4f8cba154b29dcc2e4f98faab37665780f8e95
font_01_sfnt_off00011bab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000133c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133C2 10552 bytes
SHA-256: c3bac6708ec01c312fd718a62fec6952a7c5c1c95b15d582b0e3b08c9f4c9c83

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