Malicious PDF — malware analysis report

Static analysis result for SHA-256 a78620590a3942ce…

MALICIOUS

PDF

78.3 KB Created: 2021-09-17 16:31:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5c139845f448460a0594c6bd88e74889 SHA-1: 7dca0f87af95d7f06c7973be465e1b31d0169960 SHA-256: a78620590a3942ce994d76f052b5c15a350955ce138104bc98ff89637b0e6845
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, with many pointing to compromised CMS upload directories or disposable hosting. The presence of embedded JavaScript, detected by heuristics, suggests potential for malicious actions such as redirection or further payload delivery. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://archism.ru/uplcv?utm_term=check+my+keywords PDF link annotation
    • https://ketex.com/trcgp/ckfinder/userfiles/files/zuwanef.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137b6ed62b59---soboramovutali.pdfIn PDF document text
    • http://www.520amis.com/upload/files/pewamisigud.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/18479768216.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/tetixaxabatevatej.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5f3fd923f---58199932949.pdfIn PDF document text
    • http://oilmachineydy.com/d/files/83992181617.pdfIn PDF document text
    • https://sapporopools.com/contents/files/dogowupezekazunow.pdfIn PDF document text
    • http://sms-dk.com/FileData/ckfinder/files/20210901_67DFB9AAA6FCA453.pdfIn PDF document text
    • http://tikatalog.sk/_files/file/temifofinatamimeg.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/55444148496.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/62919914117.pdfIn PDF document text
    • http://stardentalcare.org/userfiles/file/gutumuwuvizuwumutemixize.pdfIn PDF document text
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/65357855885.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161387314e23dc---pedizukukazir.pdfIn PDF document text
    • http://travelshops.pl/userfiles/file/96813225479.pdfIn PDF document text
    • http://www.bandungmesin.com/file/luxebeginafodulipugiwa.pdfIn PDF document text
    • http://mibenjamin.com/userfiles/file/26449817256.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/fujokolurimupoda.pdfIn PDF document text
    • https://sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/gegib.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/85250483877.pdfIn PDF document text
    • 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_off0000cb03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB03 10456 bytes
SHA-256: 6f06b5908f1b0a79b9cee3c7a2c832b51fab238c44dcdc552a5707a5982c66a5
font_01_sfnt_off0000e2d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D1 18868 bytes
SHA-256: 9e41a8f372b110ada0b1f0e864ca26593e37127a45b4300472dd0c9cca64d8a2
font_02_sfnt_off00011421.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11421 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1