Malicious PDF — malware analysis report

Static analysis result for SHA-256 73a18059d1145e39…

MALICIOUS

PDF

69.2 KB Created: 2021-09-27 04:31:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 459c273e88e7fd1e100528c52e29bc08 SHA-1: a2669f9b646abde0a75edb881f74ac0bb20530c0 SHA-256: 73a18059d1145e39598e61b2896e1bd3ab2f7666e99cbd9ab03bc7b2deb0ac70
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links on disposable domains, likely to obscure the true destination or to distribute various payloads. While no scripts were directly extracted, the presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614469aec4c14---bubunobijulavudulabizowis.pdf In PDF document text
    • https://grandplaza.bg/uploads/assets/file/55364597034.pdfIn PDF document text
    • https://filetorme.com/upload/files/kibakunemiju.pdfIn PDF document text
    • http://chickenwild.com/upload/contents/images/images/gomofosubo.pdfIn PDF document text
    • http://dorisemitchell.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/53009196073.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/kikam.pdfIn PDF document text
    • http://eegbiofeedback-leszno.pl/userfiles/file/sinarirusawo.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/7mqdk085nt3j9lmsna8ica8s93/12159628736.pdfIn PDF document text
    • https://tannhatviet.vn/upload/files/zisero.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021091807042462828.pdfIn PDF document text
    • https://reklama71.ru/upload_picture/77749135398.pdfIn PDF document text
    • http://themetamorphoseprogram.com/userfiles/file/bibotubez.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/99854429919.pdfIn PDF document text
    • http://lachina.cn/upload/file/6098195367.pdfIn PDF document text
    • https://kurishupally.org/userfiles/file/66941207400.pdfIn PDF document text
    • http://tiszaikaland.hu/upload/file/98818834921.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/66001757881.pdfIn PDF document text
    • https://signos.larrialdiak.es/files/galeria/files/misoxesujosidet.pdfIn PDF document text
    • http://www.bargiel.com.pl/ckfinder/userfiles/files/21614829666.pdfIn PDF document text
    • http://sxnqx.org/upload/file/Fl202109030648251899.pdfIn PDF document text
    • http://www.ufolep-69.com/contenus/files/2617217310.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/41555397337.pdfIn PDF document text
    • https://moyaexpresss.com/ckfinder/userfiles/files/87825899092.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=omega+fire+red+downloadPDF 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_off0000af87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF87 10540 bytes
SHA-256: a5e99868c472bfe2f26a12fb4029592c885eed56c37b460a89d7e8c631b21612
font_01_sfnt_off0000c755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC755 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000df67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF67 16064 bytes
SHA-256: 91313f81aceed4fdffaec959759cdb24a79140fda04a4611df19a2ad71f875e8