Malicious PDF — malware analysis report

Static analysis result for SHA-256 a37a10a5bc3dd1e1…

MALICIOUS

PDF

83.3 KB Created: 2021-09-08 06:28:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5fb6c5660c0eb188dac180b910551cb7 SHA-1: 30afa6cb519480b62a0ee43b271b4594c2ec9d03 SHA-256: a37a10a5bc3dd1e18278634a9a6d08cc91c76a1702555f1e6b309cfb534d94a7
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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 http://alexlunacoach.com/img/editor/file/dorosemeze.pdf In PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/2021510159155344.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/klmak4urosclqsfp9jr64jrcbe/xinanovoludilupupel.pdfIn PDF document text
    • http://blissrenewbeauty.com/newerac2c/userfiles/file/71304975002.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108770a7759a---kofakuv.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c022cc5b1b4---pavepakitusavowipa.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a2b67312610---13958047049.pdfIn PDF document text
    • http://teraval.cz/res/file/88072009555.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1608467b5a12cf---fugalubirapiwozefomofuxim.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/jebunubumigifaxar.pdfIn PDF document text
    • http://red-persimmons.com/upfiles/editor/files/bosutevutesubedupibatu.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b831d005411---vewomezepirobudizevikaf.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/3dae57a4feefb6aa29bb2199684b6fc2/70924198546.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/ninudub.pdfIn PDF document text
    • http://mijn-nederland.nl/userfiles/file/86816682903.pdfIn PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/mopederename.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/add77d37ef9cffea801e01849e34e71c/jusulizusim.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/xuxirozazodepokozodoloras.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160c706b3a12f3---pefisakigaxidunenufamik.pdfIn PDF document text
    • https://szallas-karpatalja.hu/upload/856082438.pdfIn PDF document text
    • http://hagelkonzept.de/userfiles/file/2871171754.pdfIn PDF document text
    • https://equator-maritime.com/userfiles/file/64965489457.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160867e64e87bf---35186358575.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/0a5c0491376af74f32418fc2ec98745c/98967029810.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c6787520f3---87926013229.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cb27e382ef4---rasunibavopeludedutuvo.pdfIn PDF document text
    • http://igs.compcierge-asia.com/ckfinder/userfiles/files/89922239355.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=manual+de+maquina+de+coser+kenmore+modelo+158+en+espa%C3%B1olPDF 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_off0000d9fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9FD 18528 bytes
SHA-256: b760e9f9f57cfe7fecb48cd21339bce355cecb6a9094298e5ebf9ee6cd66afbf
font_01_sfnt_off000109a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109A9 11508 bytes
SHA-256: 1e9c874d2c9cec5b366155b69f8987b884e660f4b51f114a98f7b712d714871c
font_02_sfnt_off00012471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12471 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1