Malicious PDF — malware analysis report

Static analysis result for SHA-256 757f4ab4bd48b16a…

MALICIOUS

PDF

74.0 KB Created: 2021-09-23 10:49:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7c2a48ada6e736a00d58cb16180970f7 SHA-1: fe71a3f74b54300bcb1cbe4fc71184cc82279976 SHA-256: 757f4ab4bd48b16a8b524ffadca051b83ac663e792fe4640e8e0f5424cb75cd7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links. The embedded JavaScript may be used to further obfuscate the malicious links or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • 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://infrive.ru/uplcv?utm_term=comic+sans+font+download+for+android
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1613cbf5765e88---vidomijizexalofakabaxurun.pdf
    • http://amsasecretariat.fr/userfiles/file/fatuzepenejefatuna.pdf
    • https://izyskately.ru/foto/ck/files/91646033399.pdf
    • http://bugskin.org/userfiles/file/94820441977.pdf
    • http://elfuklid.cz/foto/Image/file/18125559117.pdf
    • https://aimtronu.org/userfiles/file/fawutovuxorinapadivas.pdf
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/jowufikizebupowisod.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145995a56606---kinul.pdf
    • https://beauty-full.ru/uploads/files/80878754157.pdf
    • http://bafiti.com/sklep/userfiles/file/zuziruxem.pdf
    • https://nacionalequipamentos.com/ckeditor/uploads/files/32759433787.pdf
    • http://basketaci.cz/UserFiles/File/jolojis.pdf
    • https://cualuoihoanmy.com/uploads/userfiles/file/63429068534.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161415c0e63b16---31814376432.pdf
    • http://myepres.com/HotelEstimator/userfiles/file/risaw.pdf
    • http://aesg2edcv.handylover.com/upload/files/nawariwinizam.pdf
    • http://rimini-portal.de/bilderarchiv/file/35910114846.pdf
    • https://activepymes.com/pub/file/josiwimogabemapetif.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2cbbcac31---98695080252.pdf
    • http://tantos.jp/js/upload/files/gubuxi.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16140a862aae68---verunomakepof.pdf
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613fa66bd8683---25486510880.pdf
    • https://alsultantrading.ae/userfiles/files/laxawi.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bcc8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCC8 16792 bytes
font_01_sfnt_off0000d4da.bin
1c3de66a580e2474ff146f54afd6ccb2ab8b42f6d931d9053facd478ae37edb6
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4DA 17308 bytes
font_02_sfnt_off000101f1.bin
34904318ab970dade3f7ef4dd5ff76933c1d8bee7b1fa06b40cead39cc4e5cc7
pdf-font-stream PDF embedded font (sfnt) at offset 0x101F1 10624 bytes