Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b759b4f839611b3…

MALICIOUS

PDF

85.3 KB Created: 2021-07-15 14:51:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 99250032fed1313d0ff6b694754f2ecc SHA-1: 25e5f7d62ae8f10c5b340aea438dc7bb5ceea79c SHA-256: 8b759b4f839611b3e668c580a86f4bdeb5d240916b9756edc9ff6d51fc579de7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. Additionally, the document exhibits characteristics of a link farm, with numerous URLs pointing to other PDF files hosted on various domains, some of which are identified as compromised CMS uploads. ClamAV detection and ML classification strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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.bandungmesin.com/file/nukoj.pdf
    • http://aimic.com/userfiles/file/favafasidi.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078deacf305a---robojatumonosi.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a041ec69a93---67285574002.pdf
    • http://epmachine.ru/d/files/16709850662.pdf
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081ec13a6fdf---43898447567.pdf
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/408504de51c80e0558bf292e260c4a3b/20113541937.pdf
    • https://perfecthospital.org/FCKeditor/file/getivofaxudukidalefaki.pdf
    • http://izdo.org/img/userfiles/files/fesulufizamatur.pdf
    • http://barbusci.it/maisUserFile/file/xefopijijajexo.pdf
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/682qqvsel9sajoee5f55sa3dvt/29545560595.pdf
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/5339de7c4afcf1e252fd3ef82960d6f4/xexinobofapidarolonegor.pdf
    • https://radiosmile.hu/upload/file/59378671218.pdf
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/20055843115.pdf
    • http://greece-ex.com/images/blog//file/68552893092.pdf
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b011151f9ea---gasasu.pdf
    • https://sgdivorcelawyers.com/wp-content/plugins/super-forms/uploads/php/files/338da51d22d43bc2fe6af1f3ecd2e6b2/66343684195.pdf
    • https://menu2uplus.com/images/file/40231177513.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/1a55a4f81ae4b8ed787b5c116680ea17/zofuvuteterifenebafu.pdf
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b98a7bca383---daxapire.pdf
    • https://imahima.xyz/js/ckfinder/userfiles/files/89758762306.pdf
    • http://covinahigh1980.com/clients/1/14/147ee80f0cf2e08ca1b5067d21485a43/File/47219101248.pdf
    • http://beijinghuojia.cn/userfiles/file/30313896009.pdf
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/0f75b811ca8d54583311f068f8d70461/17014597781.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=photography+basics+for+beginners+pdf
    • 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_off0000e83a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE83A 16792 bytes
font_01_sfnt_off0001004c.bin
06c617296fae60ef1fd57ead75f3c5852f28646bcb029e619eb5e2385922abcc
pdf-font-stream PDF embedded font (sfnt) at offset 0x1004C 17028 bytes
font_02_sfnt_off00012c8d.bin
36f69f2cfa6d44cc1977897a89b8f504abe4f786eccfc7043620afbc3ea23454
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C8D 11108 bytes