Malicious PDF — malware analysis report

Static analysis result for SHA-256 923a640053470ea1…

MALICIOUS

PDF

71.4 KB Created: 2021-09-24 14:01:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5e7a31eb73e04b97df789eebaebeef1f SHA-1: ee563e428ec3bf70281f49f37c3e3ad0d61052a3 SHA-256: 923a640053470ea1dc9c0b7fb401122dde563bcaa01cf8b8b4db25c06a7cf823
156 Risk Score

Malware Insights

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

The PDF contains numerous links, with several pointing to compromised CMS upload directories, indicating a potential phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The file's structure as a link farm on potentially disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://trongtinpc.com/luutru/files/wifurokoz.pdf In PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149158e8b9eb---90591618412.pdfIn PDF document text
    • http://sasolution.kr/userfiles/file/fopubuvewibaxuno.pdfIn PDF document text
    • https://dwitunggaljaya.com/sitefiles/file/62637496283.pdfIn PDF document text
    • https://nirkongrp.com/ckfinder/userfiles/files/14271565899.pdfIn PDF document text
    • https://xn--90ah6akb9e.xn--p1ai/f/file/degakuxezibutipu.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/65479925196.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/46245555449.pdfIn PDF document text
    • http://travellightnepal.com/userfiles/file/49737996101.pdfIn PDF document text
    • http://ersenergy.com/UserFiles/file/xenewa.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/xadogosibo.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/doxemajusezu.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/68463034765.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcdf620e10---93438890396.pdfIn PDF document text
    • https://living-stone.lu/userfiles/files/21550295094.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/fbb11a4b3b8e6be3aec410656fab19dc/dedalakalizewi.pdfIn PDF document text
    • http://montagnobozzone.it/userfiles/files/46587244423.pdfIn PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/39590991483.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/kosekopuwovanod.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/10725992861.pdfIn PDF document text
    • http://clinicaveterinariagussago.com/userfiles/files/velujadok.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/161474e30cce44---zubakamewiposufudikoxuxe.pdfIn PDF document text
    • http://oreoltour.ru/sites/default/files/file/kazepatopo.pdfIn PDF document text
    • http://cleversystems.ru/userfiles/file/21992793096.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=why+is+tropical+rainforest+importantPDF 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_off0000b438.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB438 16612 bytes
SHA-256: ebfd62b7b00ef40b3e4d2b4bc9177126170e3f402a6cfc809153d115b45959c4
font_01_sfnt_off0000dea2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f6b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B9 10852 bytes
SHA-256: c10e86fa0fbfabe3ddcaa53475d939ef488c4e766360549f36d66d844cb3a820