Malicious PDF — malware analysis report

Static analysis result for SHA-256 a13dc25e943b5c34…

MALICIOUS

PDF

83.1 KB Created: 2021-06-26 09:20:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 8a4a1b318cf36e6dfac12dfdb1452f6c SHA-1: 128bd9128b506b5c574ed3d4d682f41ae3f54ccb SHA-256: a13dc25e943b5c34087883d42b182fd2ae45667d456e0dd3c50811bceb4b97a8
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many embedded URLs pointing to compromised CMS uploads and disposable hosting. The primary purpose appears to be directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/92f7648be435f935c88d8f649c8d35ba/85512081389.pdf In PDF document text
    • https://bilalyapidekorasyon.com/userfiles/file/66021487677.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/4083225587.pdfIn PDF document text
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/889d9794f533681c69e8e536243e7e48/gexotorukidiwolimupibi.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c5f39ed878e---32860495023.pdfIn PDF document text
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/67959174488.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6b7a858af---xiguxuritefuxun.pdfIn PDF document text
    • http://hkt-optics.com/hkt/images/userfiles/file/86198763816.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160894c60c8046---juwiwazujo.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/gobezadavesufonokaxevivij.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/o6v7ig9etas8kuethvq2jmam8r/latig.pdfIn PDF document text
    • http://bezpiecznamlodosc.org/files/file/gudamobasibavile.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/065589f077c8854a05371cb2bac65d19/vabuti.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/14975906522.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160819d141b68a---21115196843.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cabde18d021---97917933381.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/a801c9ba1bb1a9c2ba9fafa7ee2c1726/kametejapidibe.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b4aaff0e39b---wivomutulemagawal.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160cb36442cbaa---jaladivagajilotebofe.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5991a87e3---53216845169.pdfIn PDF document text
    • https://medicentrumnz.eu/medicentrum/files/file/lewanigiburoside.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/932f6b5cfe08784289c7487d96a2809e/19866002515.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/1de498f4a2124dcd0297280ec59421d0/74395431789.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa70f0cdb8---59817044491.pdfIn PDF document text
    • http://jarosi.hu/files/file/85961542596.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=be+irresistible+guidePDF 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_off0000e22b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE22B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fa42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA42 10328 bytes
SHA-256: a59b453af9d12e54cda5c38a745e9460fd943ca5f4521ec3e2c481ac9b25e0ff
font_02_sfnt_off00011177.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11177 17544 bytes
SHA-256: b8b1052d26113e69be96adf5991e4588073fcd1c4f796f557b4314c06e42c740