Malicious PDF — malware analysis report

Static analysis result for SHA-256 855a481e89e67d8f…

MALICIOUS

PDF

102.0 KB Created: 2021-07-21 15:22:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 03a82138645d34658b6503f1f64c5d78 SHA-1: a79dd3fe197adcd7d4ca0b4185499d6f8102f7dd SHA-256: 855a481e89e67d8fffb611030850637056f8a71dfa1c9f9c429ae415e4d41d24
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse. The document body is unreadable, but the heuristics and URLs confirm the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://rozgarnetwork.com/ckfinder/userfiles/files/tixuwawejotumeleze.pdf In PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/cd585e9f9320cd54989a38742e72a22c/kegugavazasu.pdfIn PDF document text
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/95b4a10dceab4e6ba86b7f1d509f7e45/fetigefetepegazod.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/80e7e61e68edf5711289d3ec665b92e3/19654932236.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/86966804012.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8fc111dc3---46794145584.pdfIn PDF document text
    • http://app8itebarandgrill.com/admin/images/file/52762755084.pdfIn PDF document text
    • https://iohrp.org/f_files/files/1635114031.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/87577612071.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/a1b35999a2b8cfd1cc9f75b238514eb2/rosavofobiradut.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/58248855818.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/cf9c2a8831480be0e23682b702fd6617/zurifezuradalajogij.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/28220894733.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/gukojej.pdfIn PDF document text
    • https://hardlineconstruct.ro/app/webroot/files/userfiles/files/32230911398.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16096bd59bfd56---xolofemur.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/gapipurenofogedivi.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1609d902d81b7f---golob.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/16098856c0a348---80688834802.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/96208b7a8e0b9f37c30d9598a0fc3f4a/43403532793.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/77626916686.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/80591993476.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/zesinapisop.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/62011346602.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=list+of+mnemonics+science+and+mathPDF 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_off00012993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12993 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000141a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141A5 18308 bytes
SHA-256: 4b8a455242c2a367813357782560d54e2b6de6e7d80a7b85b1dcb15059644ed5
font_02_sfnt_off000171f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x171F1 10552 bytes
SHA-256: 102ad1b6a126c6be701520c3fabe849ab9da0e05d599f4d4b023e3cf94997707