Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f143b8d1cf77e7…

MALICIOUS

PDF

84.3 KB Created: 2021-07-21 23:44:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5cee53d53f37c6bdd410fc8140e5cc12 SHA-1: ff6ccb9c9c4e96718f675d235ef2ce5ff88ae7e6 SHA-256: 28f143b8d1cf77e756d2775414b75cb501fd9ba27b4ff5feca39fc033e44197c
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous unknown URLs suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 https://renetravel.ro/images/files/26037459939.pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/21d8ff7e03638f4714b98b056a6b13cd/zuvavusujatu.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/us3pmvfus1l9079j6gf03402dc/22516388913.pdf
    • http://kinel-hunter.ru/upfiles/file/puwidenojenela.pdf
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608738a252043---49096964148.pdf
    • http://bogaarchitetti.it/userfiles/files/13008598701.pdf
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/p6c1hn709f0klnlmk4cqk6g7rl/jitobotizatijeweliwob.pdf
    • https://yarpaket.ru/userfiles/file/72769586222.pdf
    • https://tomas-music.com/contents//files/27175611634.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160afc58b9123e---fabajatadinatovozevusi.pdf
    • http://thaiboxes.com/piceditor/file/xizadi.pdf
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f9e9b55536521ad82a3c8b16f541f734/tezeberuvibafajoremujele.pdf
    • http://allmedicus.com/userfiles/file/lewomirerixuwede.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16096485f22d97---xutikoluvipeka.pdf
    • http://phunggia.biz/userfiles/file/tubefuluwej.pdf
    • http://agro-partner.com/Image/files/87297690872.pdf
    • http://compufoxmail.com/userfiles/file/kokulamo.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-6-5/20210605021847875975.pdf
    • http://skrabl.pl/www/rpbd/fck/file/pemufeforitumigotej.pdf
    • http://chocoenglish.com/_UploadFile/Images/file/kopatokipiw.pdf
    • http://hotelborgodeipoeti.com/userfiles/files/36889307246.pdf
    • http://zjhywt.com/images/upload/File/vatuvajifek.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=25+adverb+of+manner
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e813.bin
ff65fdb12ff15bafeb85f2e5bc44b0d98a263070b48b49792a7d128311bb131c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE813 10476 bytes
font_01_sfnt_off0000ffe1.bin
744266dfa1dc67d23abdb4df7c9907cdbdc8541288c19e9a395e169b92b43aa1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE1 16960 bytes
font_02_sfnt_off00012be1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BE1 16792 bytes