Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab422e451d793aeb…

MALICIOUS

PDF

77.6 KB Created: 2021-09-30 19:11:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6fa356e5903632dbce83a5201b2c3aae SHA-1: 43e39a12bf272146ddf5aeca2a2f17b5eca5ea95 SHA-256: ab422e451d793aebcee75497a015070d5edeebd5f12ed833d6a3c5097041a7c3
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress uploads or disposable hosting, indicating a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights this behavior, suggesting the document's primary purpose is to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://nomylo.ru/uplcv?utm_term=android+pptp+vpn+unsuccessful PDF link annotation
    • http://minuspk.ru/minuspk.ru/userfiles/file/pifudasaz.pdfIn PDF document text
    • http://olgapolyakova.de/files/files/76496839989.pdfIn PDF document text
    • https://factorysales.com/userfiles/files/gokidedoteru.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/21205508964.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210914_7F51346A9547F046.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d7e73ad41e---71015460605.pdfIn PDF document text
    • http://www.chubsorn.com/file/files/giwazitufaxuvin.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/54732157638.pdfIn PDF document text
    • http://shriramashramssschool.org/userfiles/file/6637768481.pdfIn PDF document text
    • http://astorandblack.net/emailer/userfiles/file/ruzam.pdfIn PDF document text
    • http://stellar.ru/ckfinder/userfiles/files/fivobobezomuluperinoj.pdfIn PDF document text
    • http://aptekainternetowa.net/_mdm_apteki/file/pevewaba.pdfIn PDF document text
    • http://abwmarlboropike.com/uploads/files/wadaminulijegusagu.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16151dcad9eec1---23797417527.pdfIn PDF document text
    • http://skkouty.cz/ckfinder/userfiles/files/xolixonolanorigu.pdfIn PDF document text
    • https://zufiks.pl/uploads/userfiles/files/54904094863.pdfIn PDF document text
    • http://tatagz.com/uploadfile/files/76041096193.pdfIn PDF document text
    • http://multi-accueil.fr/ressource/site-image/files/53465726653.pdfIn PDF document text
    • http://3wsystems.com/shipinc/userfiles/files/pavefapikorobudi.pdfIn PDF document text
    • http://ncfc.com.tr/ckfinder/userfiles/files/larirojarimoragodol.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/5c7edc60f4958cd783f4aec3b164edcf/15454736980.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/d68b85e7118ac75b28b64643ae53351e/wijumutezosewoletegokire.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/55104842174.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/97997602420.pdfIn PDF document text
    • http://ikkosushi.com/uploads/files/51140078716.pdfIn PDF document text
    • 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_off0000c489.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC489 19120 bytes
SHA-256: fa1eb9c7762c0374b74240e0a97ac37ca754c43c54742566b23cc7e4b162f92a
font_01_sfnt_off0000f6e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E9 10596 bytes
SHA-256: ec350a302d0d03232349e73e6c2fb15b5890a7e5ce1b9e69f95d3b9441ba9562
font_02_sfnt_off00010f48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1