Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a33a899d66b85a7…

MALICIOUS

PDF

79.6 KB Created: 2021-06-27 06:22:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f4616fdbb557ca9f3cf38701c7f81e57 SHA-1: 52fae9a23b3697337a19768cc0f0dfa9ebf1a19b SHA-256: 4a33a899d66b85a7e7cbf3be0bdd5a679cd2f6b3afd2495a4af9d97bc8aff3dc
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to various websites, many of which are hosted on compromised WordPress installations. The presence of an IP address literal in a URI and the ML classifier's high confidence score indicate malicious intent. The document body is heavily obfuscated and unreadable, suggesting it is designed to obscure its true purpose, which is likely to redirect users to malicious sites for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/969465bbcfe80018a5eaf4ef8f0725ea/19651207876.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/9507d11ad2fc5611098704d7fc495189/63977029713.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/unp999unhds8cvj7je1tuddvan/22244855830.pdf
    • http://moyamoya.center/images/hand_uploaded/files/14339635768.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/f34134c637689c71b50cb8b0ad8e517d/fuvetadozeginiw.pdf
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608ab4184ccd2---65091538093.pdf
    • https://clifestyle.net/uploades/userfiles/file/zenalobi.pdf
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/16080d5f0ac4f1---80672773975.pdf
    • http://auchli-appenzeller.ch/userfiles/files/vikowinibedulilapexukipiz.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a49a208b2fe---33300762515.pdf
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/86bc4aaa9f7b8bfd2cd04108a8a97db4/wodaneno.pdf
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/16091812ed689c---70667900591.pdf
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/9d9bc1735ba9291632cb7b277fc6a35d/mitoxadef.pdf
    • http://skogsformedling.se/bilder_umeny/File/koginavazupiwij.pdf
    • http://naturallabs.de/userfiles/file/xovuraxepeleresuje.pdf
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160b7a5c98366b---wujugopim.pdf
    • http://agendatourvietnam.com/hinhanh/file/tafax.pdf
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160871853d0213---40322128426.pdf
    • http://naturabliskociebie.pl/userfiles/file/gidefuwigezovijulefuregum.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/0mcat0nlh92070p424alk729t0/finilaxizi.pdf
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b96e61ec485---36364777866.pdf
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/3e04827b0e6d2194b10f1c204b0e6a89/22755223946.pdf
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607162b3400a9---gujixag.pdf
    • http://dgjst.com/upfile/file/39563086055.pdf
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/dd27097073baba35aa6ead8a02702326/luzasolonobedufapuvudaj.pdf
    • http://clairvoyantinfotech.com/demo/images/piratonetemesefepife.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=pure+yellow+colour
    • 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_off0000d614.bin
0d3262ab9e66cc1b0c8f96b354523eed8943fbc274deffdaf82adee8d6815ecf
pdf-font-stream PDF embedded font (sfnt) at offset 0xD614 9900 bytes
font_01_sfnt_off0000ec1d.bin
de683268dabfe4bee8320b2a09f2eb83bfee73e456596d331f01dd3908f4260b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1D 17124 bytes
font_02_sfnt_off00011906.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11906 16792 bytes