Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8785bb7a7618215…

MALICIOUS

PDF

81.7 KB Created: 2021-09-03 16:38:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e206f5464288415c0ff34ccad8cd2f49 SHA-1: c987465e2bbf623ad2aeb8dda172183655fed8a9 SHA-256: e8785bb7a7618215be81b811da1a757582516f589d6642205dae90217614f5ce
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable hosting domains, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm its malicious nature, likely serving as a phishing lure or a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://bikaji.zohukum.com/ckfinder/userfiles/files/tuxewudunisewunefiwuj.pdf In PDF document text
    • http://tivati.com/uploads/userfiles/file/dupizexikasokebaxaj.pdfIn PDF document text
    • http://modern-pro.ru/files/file/vebusojasupigipoj.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/66001213373.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/86578201715.pdfIn PDF document text
    • http://dalaichau.com/files/21543898917.pdfIn PDF document text
    • http://www.alquilerbares.com.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5f2c49ddc---59148790067.pdfIn PDF document text
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/jazubuxoritobogutovoneni.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/g5udic75auoh9qsd28t7g8uuv0/1590823923.pdfIn PDF document text
    • http://matchedtubes.de/userfiles/file/68444930604.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/zezizatel.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc2dd08a7f---mowaxavok.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/77914486010.pdfIn PDF document text
    • http://jucal.es/images/file/81287245426.pdfIn PDF document text
    • https://eobliecky.sk/userfiles/file/59813383368.pdfIn PDF document text
    • http://195exim.com/datas/files/83651567844.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/kamimivimituzatamisunob.pdfIn PDF document text
    • https://www.deuba.info/wp-content/plugins/super-forms/uploads/php/files/74tnmelmtect3e196oaeckq8bs/39343077692.pdfIn PDF document text
    • http://mextro.de/upload/files/75687509868.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/98vubhr77ihio3fapfhe37uggs/jujejuzebasupokoxe.pdfIn PDF document text
    • http://atdawnwelift.com/userfiles/file/41899943192.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/lafuvufubupolivikexaxoka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=jaguar+f+type+manual+transmission+for+salePDF 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_off0000d635.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD635 19064 bytes
SHA-256: b9ffd4b1eb754b5ce07ddcaf1172b5d7c907ec0b22d829307f5d5b37ab2492a4
font_01_sfnt_off000107a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBE 10908 bytes
SHA-256: 08ca07140f8cef273bc24e58f6dbf64e750a555b82c45b56ae11a91604c3a499