Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b7ced1764c4435d…

MALICIOUS

PDF

75.5 KB Created: 2021-09-19 07:35:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 52297e1cf50bd50685f1f8c15db9fbd3 SHA-1: eddf7244fb60e8135611216b7694a84d044d5161 SHA-256: 6b7ced1764c4435de4ce6716e5877ae1f4515f741e57b2440041034e1cbd8d04
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The presence of embedded JavaScript and a large number of external URLs, many pointing to disposable domains or potentially compromised sites, strongly suggests a phishing or malware distribution campaign. The document body is heavily obfuscated and appears to be non-readable content, further supporting a malicious intent rather than legitimate document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

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
  • 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://crewmak.ru/uplcv?utm_term=caused+by+java+lang+nullpointerexception+in+android PDF link annotation
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/ee13d51c7b50990313d4916f658a67b0/26867660499.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/pefasev.pdfIn PDF document text
    • http://skkl.cn/filespath/files/20210917123704.pdfIn PDF document text
    • http://geojeoceanhotel.com/userfiles/file/20210914113424.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/lilukidalafizasekumo.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/f9g71586nv1uihlbuq8bi5eg4n/3959360932.pdfIn PDF document text
    • http://myxroad.net/upload/userfiles/file///tugexor.pdfIn PDF document text
    • http://seidels-mineralienwelt.de/images/uploaded/file/66510004428.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/47596305382.pdfIn PDF document text
    • http://www.lbtfilm.com/uploads/files/xozuxuf.pdfIn PDF document text
    • https://cargobull.cz/res/file/pakepanudusanogironinewa.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210913092046.pdfIn PDF document text
    • https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/12364727408.pdfIn PDF document text
    • http://vandientuchinhhang.com/upload/files/puviximizavote.pdfIn PDF document text
    • http://worldplastsolution.com/ckfinder/userfiles/files/juzuwawovur.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/15611471108.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/wapipasozamemubasig.pdfIn PDF document text
    • http://patrick-jardinage.fr/ckfinder/userfiles/files/kabugulupugorodujuxa.pdfIn PDF document text
    • http://zeci.nl/im/image/92220533180.pdfIn PDF document text
    • http://willbramephotography.com/97890963587.pdfIn PDF document text
    • http://jarauwerdaenzn.nl/userfiles/file/pizuvofuwi.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/dalugi.pdfIn PDF document text
    • http://kzlo.pl/fotki/fotki/file/nezorivuvetarabogizi.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ae00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC611 16284 bytes
SHA-256: 5ba10fc9be211ff4c2c9590eb88ab9ad0a9cd021f9f8acba9a4d8ad4907cfeb7
font_02_sfnt_off0000dc3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC3B 11372 bytes
SHA-256: 467d014e9a09ae55776fdb5daa0359a93eddb8fba6b82a206b44b54b43b5748b
font_03_sfnt_off0000f6bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6BF 15568 bytes
SHA-256: 21a7b6b1ab91565f5245faf762d939b6eb0662313c1a8a889d71aefd854d9c4b