Malicious PDF — malware analysis report

Static analysis result for SHA-256 90e9aa38da7e9b39…

MALICIOUS

PDF

67.4 KB Created: 2021-09-09 06:00:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7d6df2454e4bb75d89598805e6309df6 SHA-1: 1595d4912187098ccb3ff30f9398cf30027df0bf SHA-256: 90e9aa38da7e9b393a677b8bbad25545f0a303e993d30a85ff82417b72883988
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing lure. It contains an embedded JavaScript stream and multiple external URIs, with one specifically identified as a link farm on disposable hosting. The document body is heavily obfuscated, but the heuristics indicate it's an image-only document designed to trick users into clicking a hidden button, likely leading to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 67 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://nguoixunghekiev.vn/userfiles/file/digazanamogotitelokunete.pdf In PDF document text
    • http://soles2walk.cz/data/file/62854332682.pdfIn PDF document text
    • http://mrpennarak.com/user_file/file/82866314775.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/78659785599.pdfIn PDF document text
    • https://netlandschool.cl/files/20203844852.pdfIn PDF document text
    • http://plovdivweek.com/app/templates/js/ckfinder/userfiles/files/liziza.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/fowigidu.pdfIn PDF document text
    • https://prettygreekvillas.com/admin/fckeditor/editor/filemanager/connectofile/zinajirebukajulodorurejor.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/86478355924.pdfIn PDF document text
    • http://viethanit.vn/hinhanh/file/dimazekagoz.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/89427932207.pdfIn PDF document text
    • http://somersetcountybar.org/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/74011862129.pdfIn PDF document text
    • https://alternativi.brtim.com/uploads/wysiwyg/files/68034065292.pdfIn PDF document text
    • http://clinical-pain.com/pds/userfiles/files/nituwivivikif.pdfIn PDF document text
    • http://janjoling.com/public/ckfinder/userfiles/files/wemuxidonozivufiwigugovet.pdfIn PDF document text
    • https://rwd1.thadv.com/upload/files/91497045363.pdfIn PDF document text
    • http://sjmhospital.org/files/js/ckfinder/userfiles/files/sutezigu.pdfIn PDF document text
    • http://jaatkinson.com/userimages/4076803762.pdfIn PDF document text
    • http://heathrowairporttaxi.website/userfiles/file/rasafabexememuvitisavusa.pdfIn PDF document text
    • http://terremeraude.com/userfiles/file/gefuki.pdfIn PDF document text
    • http://savitapiti.org/ckfinder/userfiles/files/30307989276.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/2qnqtesjkll0i4hl0rsoaaejmq/43024017543.pdfIn PDF document text
    • http://storemisr.com/uploads/files/57178870051.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=dolphin+emulator+pro+androidPDF 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_off0000adc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADC7 14036 bytes
SHA-256: 92c7f1c50f8e7f71173c3ebece5019db3e36b91b46f052c6dea2c9c46b3ad8e6
font_01_sfnt_off0000d07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD07E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e895.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE895 10592 bytes
SHA-256: 02b8ce372f947154feb0398b8079600d2cafdd3bf2a781582929bb7e71cf3d0c