Malicious PDF — malware analysis report

Static analysis result for SHA-256 39f76fa0b1c268fa…

MALICIOUS

PDF

83.9 KB Created: 2021-06-25 13:01:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: e917f64e8a76e34620ec6a618cc1594a SHA-1: 004d394fd721cd08965bb8e99f008fb40b68bf91 SHA-256: 39f76fa0b1c268fae3fc96ec8412a653b9440b83d356f7f7e6ce3926545a6412
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to compromised CMS upload storage, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a vehicle for the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/6d55f0d73098d6e945a4702e18659872/zofigidinamutoxenimapom.pdf In PDF document text
    • http://guides2alpes.fr/uploads/file/58985047910.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/g0t55d7lumsm6ooe4dfq2m6hfa/kugewotezu.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1c75a31a65---4252602497.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/39503785587.pdfIn PDF document text
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/95o83grqpu4u11auu0pm7p6726/senof.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082d86ed30d3---88029479818.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160beaf7fea26d---17555224564.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abd46524bd8---83051580520.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160acaf599e273---lewegovox.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7055187234---toperu.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd511c960b9---75476548400.pdfIn PDF document text
    • http://bigxra.com/uploadfile/file/2021051308434373499.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160c8b73db7943---53704197730.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/mevogotinutowe.pdfIn PDF document text
    • http://wildpflanzen-planung.de/file/5195497747.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607a79f16cafb---61166219610.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c4ac1857e---5309894015.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=arcade+with+bowling+alley+near+mePDF 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_off0000e144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE144 17696 bytes
SHA-256: 8c2c3ed93999839fa58dbd8ee3d1cf7ddf20573b68932b6fdc2919569e01eb03
font_01_sfnt_off00010ff8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF8 10968 bytes
SHA-256: be94f4d51bec1ae70e86aabde56526cca1d47c696f379b9527af01b0cd975fa5
font_02_sfnt_off00012918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12918 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1