Malicious PDF — malware analysis report

Static analysis result for SHA-256 421b29a1331427a0…

MALICIOUS

PDF

68.7 KB Created: 2021-09-23 02:53:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2389a37899c14534fd846ec0c117e988 SHA-1: b971907d05432e90b6b125fae359e697e8fd0f04 SHA-256: 421b29a1331427a0771a3af7173cf1d6f35800e435ddb0256b803fc99571331b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm pointing to various PDF files hosted on compromised WordPress sites and disposable domains, with one URL specifically mentioning 'download idm apk for android'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure suggests a lure to download further content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 https://pistant.ru/uplcv?utm_term=download+idm+apk+for+android PDF link annotation
    • http://faw-asia.com/image/upload/files/ruzasisa.pdfIn PDF document text
    • https://bdblue.com/ckfinder/userfiles/files/zuzuterogitifolotidekimo.pdfIn PDF document text
    • https://scmsgroup.org/ckfinder/userfiles/files/50804583196.pdfIn PDF document text
    • http://nemdanangpho.com/uploads/2021-09-17/images/files/lajixexewin.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/bodavap.pdfIn PDF document text
    • https://fisheaglesafaris.net/pics/user/file/29436888911.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/vemumum.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/tirek.pdfIn PDF document text
    • http://bongoes62.dk/userfiles/file/xufoledetixevosafuteti.pdfIn PDF document text
    • https://autohausnschmidt.de/userfiles/file/nutuvatudetikudexaninaber.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613907d360838---xagir.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///78558156231.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/muketowulup.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/pufegorelovepuvox.pdfIn PDF document text
    • https://menokatea.com/ckfinder/userfiles/files/jelafiwa.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/11a1fbed9c834e44a0a6782a1519e25b/34833246340.pdfIn PDF document text
    • https://hoangphatdanang.com/uploads/image/files/87853134941.pdfIn PDF document text
    • http://logo4you.dk/userfiles/file/pexewonanepefufiladujal.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161451c066372d---belepapatetufabumixe.pdfIn PDF document text
    • https://ocw.tw/uploads/files/16922385858.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/kavemitupevelebulosobef.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613fbc78e7c9d---50659717812.pdfIn PDF document text
    • http://studiotecnicopetrillo.eu/userfiles/files/selajufexerenotujota.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_off0000b214.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB214 10440 bytes
SHA-256: 11efdeac6185314128c6b1e833815fa34f5a6ec0f0794f205390a72a7cb8ca11
font_01_sfnt_off0000c9a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e1ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1BA 14164 bytes
SHA-256: bd2d75f663c03ff0a0d934bffff0435676daca4b3a46b548f527656182f20f09