Malicious PDF — malware analysis report

Static analysis result for SHA-256 ddc54cd681fe8eca…

MALICIOUS

PDF

74.0 KB Created: 2021-09-16 12:03:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e442c55a4aae7cd38d3ca33b53260f67 SHA-1: 1a9fe4abed13fb81630029e23e8684ad5bf7da09 SHA-256: ddc54cd681fe8eca370d1c61639d7bfc2d3a5594da84e77a44bc2ba2a1fa89ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to disposable hosting and are part of a link farm, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/91heguh71c2cddoiri1tnjg7um/xuvijujamolijagufuje.pdf In PDF document text
    • https://m-astar.com/UserFiles/files/53549595969.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/57204077490.pdfIn PDF document text
    • http://ducthai.vn/userfiles/file/3927135210.pdfIn PDF document text
    • https://aymsoft.us/aym_image/files/paburele.pdfIn PDF document text
    • http://namhungholdings.com/uploads/ckfinder/files/62765089436.pdfIn PDF document text
    • https://businesslife.com/content/files/44558764419.pdfIn PDF document text
    • http://saktigroup.in/uploads/98537622947.pdfIn PDF document text
    • https://alutat.com/data/file/91349340732.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef7ac9363c---46461775326.pdfIn PDF document text
    • http://pk.mo/userfiles/file/dubebanoluvefaxe.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/60063647871.pdfIn PDF document text
    • https://veaodaibrahma.com/uploads/image/files/38035073796.pdfIn PDF document text
    • https://rosycaffe.com/file/deveretufebex.pdfIn PDF document text
    • http://damvua.com/damvua/public/images/files/fupavusivexu.pdfIn PDF document text
    • http://coeb.eu/userfiles/files/xakefajafufufuratu.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/mizazelup.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/68583439685.pdfIn PDF document text
    • http://hkwwta.org/userfiles/gusuzogobozevoriludokezu.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ddad8d8610---81626421214.pdfIn PDF document text
    • http://meskerjager.nl/media/files/razenosatifenijek.pdfIn PDF document text
    • http://toitureetfacade.fr/data/Files/fawolaperibi.pdfIn PDF document text
    • http://skrutit-probeg.ru/upload_picture/file/28305415250.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=can+you+cast+iphone+to+android+tvPDF 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 extracted file (font_00_sfnt_off0000bf97.bin)
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn extracted file (font_00_sfnt_off0000bf97.bin)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bf97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7AE 10876 bytes
SHA-256: e044ca24029e808886e71038f5858ff3fa6d6ca390fd1ab229b5c116e6b3e85a
font_02_sfnt_off0000f0db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0DB 16252 bytes
SHA-256: d9e4ab62e7aaec60f6118b4dbe0adb5ddc1bf5fa0dadb62940749a5d5f280672