Malicious PDF — malware analysis report

Static analysis result for SHA-256 d57db321cc2cdaa9…

MALICIOUS

PDF

85.0 KB Created: 2021-06-25 16:03:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 83f745694409073ce87109b779cbf9eb SHA-1: c2df9b3dd75c4cf204a97b466a788e5e5157c0b8 SHA-256: d57db321cc2cdaa91e54cb6cb3df78817a494eca43964583c0b9fbaeb6ed6aa9
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to other PDF files hosted on compromised websites. The presence of multiple links on disposable hosting and the use of UTM parameters suggest an attempt at SEO manipulation or distributing further malicious content. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dc7fe82891---lunaxawovew.pdf
    • http://barsugo.com/ckfinder/userfiles/files/mozupap.pdf
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/ef194d5699b762443a3d5d7e4712657c/tesamoruxevizexakadusof.pdf
    • http://thanuyentea.com/ckfinder/userfiles/files/fabitib.pdf
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090751767a59---5168605697.pdf
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/e362257ffaace06540e3732f92c273c7/tokuvamerazitadedoragafin.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/16078067fea4a7---79505564598.pdf
    • http://brooklynsmokeshops.com/admin/images/file/46747603227.pdf
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/k9elhhkioob12mqed7kuir850n/bedomoxubar.pdf
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/89557d53df3baeb2b8da24b9e8c718e5/29929225376.pdf
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b1b65ccf3a2---turorabuxoled.pdf
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/noh032sipdnu2dsr0nb76f59ss/mixire.pdf
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a6d23dabf66---27015372359.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16072a03585567---46388253061.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607eeb73a8fe1---28645943114.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=suprahyoid+muscles+pain
    • 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_off0000eb9b.bin
e63c0384d83a22e470a3f04a857ce58029bce51807ff76ad56dea9e53b5ebb33
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9B 16528 bytes
font_01_sfnt_off00011670.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11670 16792 bytes
font_02_sfnt_off00012e87.bin
ebd5f7a9fb6320e13682c4f94ddc2638b49aef36291bc1451a044be16adf6fad
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E87 10972 bytes