Malicious PDF — malware analysis report

Static analysis result for SHA-256 91890708bf8d9b6b…

MALICIOUS

PDF

187.6 KB Created: 2021-07-14 00:16:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7ebb204c864161af499c86e3f6ac7db8 SHA-1: d86de32485f58e913dc8df0f501a9db2267b362b SHA-256: 91890708bf8d9b6b32d24792cd017184ec6e70b300ff2ebb4bba0377938ede4a
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a phishing or malware distribution attempt. The presence of PDF_RANDOM_URL_LINK and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a pattern of linking to potentially malicious content. No scripts were extracted, but the overall structure points to a lure document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9430

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://cr2tek.com/userfiles/Proj_Name//files/dekedaguwarikaxil.pdf
    • http://divapharma.com/uploaded/file/bosonavifeguluvix.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a45111bc334---kulexorobuluvesejot.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ba071b41b69---40579343011.pdf
    • http://biotledlight.com/userfiles/file///42878864560.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/08amuo463njj7l5vut7uaromv6/12527702105.pdf
    • http://renovfab-menuiserie.com/userfiles/file/kuferazegexuvuxoramefuv.pdf
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608de8b094a9e---66872772043.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a32e453e4---jugafaderifalujokejagufu.pdf
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16072f87f2fce0---52067777951.pdf
    • http://iphysiology.ru/upload/mokekexafupuwaj.pdf
    • http://mobilni-kadernictvi.cz/files/file/tugudedefozenagofiw.pdf
    • http://www.alfapilates.pl/upload/file/19630455825.pdf
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/9fd1ajrd06ng76trmp0t1l5end/sasolejopav.pdf
    • https://observatoire-omic.org/documents/file/nopavuniwurajomigapam.pdf
    • http://burelomdo.com/ckfinder/userfiles/files/41119820046.pdf
    • https://bomberosdenavarra.com/userfiles_nexo/files/77721330598.pdf
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16088d7f74e061---17568151037.pdf
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/4298e5f8825aa15fc8e05d8aa0cbc26e/jojovafuwabis.pdf
    • http://orvosvalaszto.hu/uploads/files/pagofozivusikik.pdf
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/ge7ghbpemadgopbai44hr9d1dj/wufavifasatopuza.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c9cc0e6ec---82031043414.pdf
    • http://citysuji.com/ckfinder/userfiles/files/45178114500.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=one+piece+episode+132+dubbed
    • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001fbe5.bin
d5fd2b016920ad120472a24930580007877805b209a23368762396412972646a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1FBE5 10712 bytes
font_01_sfnt_off0002147d.bin
eb83fb48a2f60ac59fad768156047f025764cad4052c8f34695a9c8dd2456ad8
pdf-font-stream PDF embedded font (sfnt) at offset 0x2147D 16132 bytes
font_02_sfnt_off000229ee.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x229EE 16792 bytes
font_03_sfnt_off00024200.bin
e265dfc0f368c66f82783e0cae6cd44665471f07c1ef7bb7154a5e5c6ac0c130
pdf-font-stream PDF embedded font (sfnt) at offset 0x24200 18804 bytes
font_04_sfnt_off000272b1.bin
851bcdfc513e5a5dfe5dc9c918dfe7d0410309b3e298c61c93d9997333e952aa
pdf-font-stream PDF embedded font (sfnt) at offset 0x272B1 39404 bytes