Malicious PDF — malware analysis report

Static analysis result for SHA-256 da7bf6adf940223a…

MALICIOUS

PDF

84.6 KB Created: 2021-09-21 18:10:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5ee544e86365055e569c2dcbd9ab9c98 SHA-1: 91f34c6b538cafd90ab0c0d816d6911b661a0dd2 SHA-256: da7bf6adf940223a84ebe6d39e914ae5af1cbbbfb4c554709ad56077acb5eb47
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable domains. The presence of external URIs and link farms suggests an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://szkolaprywatnaleszno.pl/userfiles/file/20583589533.pdf In PDF document text
    • http://velkoobchod-man.eu/ckfinder/userfiles/files/memuwenedurovotepat.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/kupade.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2aeab5ffc---6483760061.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/tejabolaxesexubilese.pdfIn PDF document text
    • http://islaminkiel.de/webmisr/uploadwebmisr/file/kunifokuwomuv.pdfIn PDF document text
    • http://scro.ru/pic/file/92168020282.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16312322629202.pdfIn PDF document text
    • http://tgroupsrl.com/userfiles/files/votodupawofipuwatemewapa.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16141221666536---rorolobofapisus.pdfIn PDF document text
    • https://bearings.vn/images/ckeditor/files/23771881584.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136db40d287a---38937867596.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/75ef0a650b6acc34c14f0060c787fc32/bajegudusokofemomux.pdfIn PDF document text
    • http://nutronicltd.com/userfiles/file/59381737968.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/80337846607.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613793cf1c019---1126659674.pdfIn PDF document text
    • http://kbcsisa.com/upload/fckeditor/file/gozimididunepug.pdfIn PDF document text
    • http://studiotecnicomancini.eu/userfiles/files/domizegenazugerolusiz.pdfIn PDF document text
    • http://asijskepotraviny.cz/files/file/31388410366.pdfIn PDF document text
    • https://terracell.pt/images/file/gofipubuvusaxukujokataz.pdfIn PDF document text
    • http://cathyknightwaite.com/ckfinder/userfiles/files/82863608220.pdfIn PDF document text
    • https://360clothing.indicsys.com/home/www360cl/public_html/uploads/images/files/tapete.pdfIn PDF document text
    • http://zaragozalawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zugirubetejakotukiramivir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=android+phone+with+2gb+ram+under+10000PDF 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_off0000e515.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE515 17620 bytes
SHA-256: 1dfeaf00c7353ffe93c3bf692f53bb5dd61098a0f6368306346eeae516157784
font_01_sfnt_off00011336.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11336 11224 bytes
SHA-256: 32bf38040915e6b5b4a0399f55d5dfd0480c0406c10fd8d860727132a60e66f7
font_02_sfnt_off00012d07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1