Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85f197f425a2199…

MALICIOUS

PDF

81.3 KB Created: 2021-09-09 04:28:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 674bb4cfbf3b1bb4b9653b4c1ebda7b3 SHA-1: 62aff193d798fb51bb734d975daddbacd58f68dd SHA-256: a85f197f425a219983faa62790f4cdd715829d3d00592c475f54bf69b1cf877f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised websites, including WordPress upload storage. The presence of external URIs and link farm characteristics suggests a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://smidgel.ru/uplcv?utm_term=all+reset+mobile PDF link annotation
    • https://www.gurkhasfinance.com.np/ckfinder/userfiles/files/23684654783.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/18813736397.pdfIn PDF document text
    • http://praconsulgroup.ru/pict/file/27548905266.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/riganipore.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/98156306237.pdfIn PDF document text
    • http://fszhenjia.com/upfolder/e/files/20210904085616.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/demazi.pdfIn PDF document text
    • https://fizjolech.pl/userfiles/file/baraxarodasukodidam.pdfIn PDF document text
    • https://feldmann-spedition.de/pics/userfiles/file/pafoxokekabegixutun.pdfIn PDF document text
    • http://bftt.marketsearching.com/upload/files/92891800981.pdfIn PDF document text
    • http://scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/fumifuzom.pdfIn PDF document text
    • https://noithatkuongthinh.com/uploads/files/5530968528.pdfIn PDF document text
    • http://huerural.com/uploads/image/files/1810764679.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202109071509257380.pdfIn PDF document text
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/befegixofupuwegipulupolof.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/d429743ee100f8fdff21fbe4dd6af996/81341997144.pdfIn PDF document text
    • http://grupopiscis.com/upload/files/15712401228.pdfIn PDF document text
    • http://libron.pl/fckupload/assets/file/ketukul.pdfIn PDF document text
    • https://austdoorcaocap.com/upload/files/13584952915.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef94fdec80---pivijajijunazazanog.pdfIn PDF document text
    • http://szm.hu/userfiles/file/xetunalerudumuwi.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/a546agi1015a6tg1tbt5nu4sc2/31136617940.pdfIn PDF document text
    • https://bostaninsaat.com/image/files/dufuzuvugivotegisilugi.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/8212806726.pdfIn PDF document text
    • http://musik-fachberatung-neumarkt.de/images/uploadedimages/file/7817649340.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_off0000d91f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD91F 10124 bytes
SHA-256: 12b21cbd65160d09a4d4f83130cd6c207940b2d56206e6b8e270fa42a4475fb8
font_01_sfnt_off0000efc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC1 18592 bytes
SHA-256: 89a3bb0a9342e089a4ec1fdc4ade65c076108e8ba0206c209f68f8141e55eb9f
font_02_sfnt_off00011fc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1