Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb8fe5a490d1201e…

MALICIOUS

PDF

86.2 KB Created: 2021-07-03 03:43:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a0fe990fe5389b13752b33eabc93310b SHA-1: 529396c306b8dd459db13f4351e4d1109b8599af SHA-256: fb8fe5a490d1201e23ce6a4a5361180e2ab77141a99557ef70c9f77f8c89fbea
156 Risk Score

Malware Insights

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

The PDF file contains numerous external URIs and links pointing to compromised WordPress upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple distinct hosts and UTM parameters in the URLs further supports the classification as a link farm designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://nomylo.ru/uplcv?utm_term=besse%27s+on+clear+lake+for+sale
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160d66259247a9---jamijizubikosarupakuf.pdf
    • http://dlmberatung.ch/userfiles/files/21348650288.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/jigcorlr2nb8i75vsslst7hp2j/20611374532.pdf
    • https://protradingindia.net/userfiles/file/37278635091.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16074d4bbe9dbf---39151113923.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/5nutlela5g1ad8tlqbfkm53hi7/sinatu.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/7715ee5676236df7e9efa10ac0a0c222/dasanutawad.pdf
    • http://gmei.lt/ckfinder/userfiles/files/52164300763.pdf
    • http://capitolmetrophysicaltherapy.com/userfiles/file/vinagobameximaxewomavife.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b0121d02e---padepovisiziv.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094869ac6e83---zifipesiwe.pdf
    • http://7tec.ru/userfiles/files/borapubevo.pdf
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/939def703beb3bbf22d7011e61447d13/bojizupono.pdf
    • https://ventadeterrenosurbanos.com/userfiles/file/13807040805.pdf
    • http://bjallstar.com/upload/file/gufazovivalalamaxagesi.pdf
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/9712b0dd88379e1049d3d79dbd9d804b/47061806151.pdf
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a00464c15c1---67313061065.pdf
    • http://ash-graphy.com/userfiles/file/71976374070.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160df83092a35a---38112671307.pdf
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/50f6b9d89eeac56875ab2fc6c2320f86/31141248567.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/0587373f6f4d55ef965ee6305418c3dd/20445201789.pdf
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160b24ce94346e---goboli.pdf
    • http://dhs1959reunion.com/clients/871764/File/76201331640.pdf
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/r885ack151pg4gnq81iori7a33/43951512952.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_off0000ee73.bin
81fa1aa0dddebf75da07a6ab0b83154c5724c49d1b6b93eb0f444c068b07c623
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE73 16928 bytes
font_01_sfnt_off00011a6c.bin
eda38e1b9596585a39de373c558afd8e2a5116f33a2b7f911306f93c1d1908eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6C 10320 bytes
font_02_sfnt_off000131f1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x131F1 16792 bytes