Malicious PDF — malware analysis report

Static analysis result for SHA-256 0365c5c0337ea83f…

MALICIOUS

PDF

112.8 KB Created: 2021-09-13 03:17:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8841ae3132eaa1ba3d372b1804f40021 SHA-1: 2a6e01f6c68c0e1aea13f8f97765b2e3bf62b190 SHA-256: 0365c5c0337ea83fc5891659464bf385e96539f50753e39cd88d7e65655db4df
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or SEO abuse. The presence of embedded JavaScript suggests it may be used to redirect users or further obfuscate the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

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 http://www.gamylai.vn/uploads/files/78984203820.pdf
    • https://ichibaninfotech.com/ckfinder/userfiles/files/16940162148.pdf
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613b90adbbba4---weluzajuxunegefebelafe.pdf
    • https://cdmsig.com/ckfinder/userfiles/files/11061995369.pdf
    • http://espwireless.net/uploads/file/zixiwona.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131b842dc5f1---wisaxebopef.pdf
    • http://pravkniga.ru/files/userfiles/files/kasapi.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133f63c63748---pokupexogikegozumimodinim.pdf
    • https://sieuviet.net/webroot/img/files/96620016624.pdf
    • https://idosekotthonaveresegyhaz.hu/files/files/78425353996.pdf
    • http://yey.uw52.com/upload/files/bodebupuranuxum.pdf
    • http://marsalanoleggio.it/userfiles/files/jiwutog.pdf
    • http://musclecar-taps.com/js/upload/files/givejowejinazanojowinin.pdf
    • http://dzirerealtors.com/uploads/12884205065.pdf
    • http://www.abcklima.hu/data/editorfile/jizezinas.pdf
    • https://sinarlangit1.com/contents/files/41966143072.pdf
    • http://salman-is.com/userfiles/file/xiwedixakekivesonowut.pdf
    • http://dar-tom.pl/userfiles/file/gixadiwudevetisisajifosug.pdf
    • http://bannermaul.com/userData/board/file/10517184320.pdf
    • https://himalayanwanderer.com/himalayan/userfiles/files/pejebam.pdf
    • https://ovistar-dz.com/ckfinder/userfiles/files/kebigikikexiwu.pdf
    • http://www.bluewhaleline.com/image/upload/File/wusevemavavofidafepiwuso.pdf
    • http://tabbanbros.com/admin/fckeditor/editor/filemanager/connectors/upload/file/9943508056.pdf
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/74861e98bf5ee29c1acd4d6b1d4f176e/16425849598.pdf
    • http://braghieriarchitettura.com/userfiles/files/26784049918.pdf
    • http://wsm.hk/images/files/zalovezufivodudozipozu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=words+that+starts+with+the+letter+m
    • 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_off00015769.bin
48d818f42a3a03b0d56fb2fb95181174b4875bb7b2f8f0ff3fe69795a9cc9539
pdf-font-stream PDF embedded font (sfnt) at offset 0x15769 10488 bytes
font_01_sfnt_off00016f4e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16F4E 16792 bytes
font_02_sfnt_off00018760.bin
b186613156871e354e1a75e8a7d4d8c59f38383ee3ebc403d508fa71ecc8a68e
pdf-font-stream PDF embedded font (sfnt) at offset 0x18760 17932 bytes