Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fdd71a36e173bae…

MALICIOUS

PDF

70.6 KB Created: 2021-09-28 16:47:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 21dfe1f7f37de716e6358b762d1b75f0 SHA-1: cc5d5956ed4838514c3e5bb0d9e6a3ef840f61d6 SHA-256: 1fdd71a36e173bae63568c0fd01bc8e92e56299c494633a56b40ba4949743ea4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=zenonia+5+mod+offline+apk PDF link annotation
    • https://arichaindia.com/userfiles/file/jajiw.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/zolaneganumu.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16141d87f0857f---7681383111.pdfIn PDF document text
    • http://yangs-ns.com/ckfinder/userfiles/files/20210921114827.pdfIn PDF document text
    • https://skillmapmagazine.com/ckfinder/userfiles/files/xuvaledup.pdfIn PDF document text
    • https://adverto.ee/userfiles/file/20927597141.pdfIn PDF document text
    • http://casinodanmarkjackpot.dk/userfiles/file/nimida.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021091413084973499.pdfIn PDF document text
    • https://franchiseinnovations.org/broker-site/files/files/96948428085.pdfIn PDF document text
    • http://alumcity.ru/userfiles/file/tatemumunobimonaruv.pdfIn PDF document text
    • http://hondatayho.top/img-ngocbao/files/punozekoxivenamisuvinuje.pdfIn PDF document text
    • http://perfekt-dom.pl/designhome/admin/userfiles/file/43995616208.pdfIn PDF document text
    • http://boki.hu/editor_up/89217234127.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138c2c930cc1---komufozup.pdfIn PDF document text
    • http://opt-russtd.ru/data_center/upload_pictures/file/zisaludobewawisidujolepi.pdfIn PDF document text
    • http://pogotowienaukowe.com/Upload/file/54017146971.pdfIn PDF document text
    • http://pasaru.com/upload/files/nosatomo.pdfIn PDF document text
    • https://autoradiator.mn/uploads/ckfinder/files/50807962712.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/vewekineru.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/rumol.pdfIn PDF document text
    • https://sowlindia.com/userfiles/file/29524482206.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/98144986247.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141661c7979a---rasaxubelinuzozaxasuporem.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_off0000b239.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB239 16748 bytes
SHA-256: 6998fa92128febaac43600d67dd414b87c081be60039ee959d5c227c12140f36
font_01_sfnt_off0000dcbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCBD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f4d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D4 10480 bytes
SHA-256: e16b27721f76c5caa264bd2bc4ba8afcf4bf698c3b197e46abf320bd5c75bc63