Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9a5e7fe73d825e4…

MALICIOUS

PDF

84.7 KB Created: 2021-09-22 09:38:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e5a29bba7027df662512e0f67230b07d SHA-1: 790b12cd8cf57b46c50330f278c83c1b073dc14d SHA-256: d9a5e7fe73d825e41dd06e9fc4add9f06e8da35166901ddd476eb4378982b78a
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://at-studio.tw/app/webroot/userfiles/files/20210921_061927.pdf
    • http://goodwill.pl/userfiles/file/97146725446.pdf
    • http://alda.pl/ckfinder/userfiles/files/37008871401.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613bba5926643---50891086782.pdf
    • http://francescasciortino.it/userfiles/files/tigugabusegozuxurileje.pdf
    • http://yuh-tarng.com/userfiles/file/jijexexipasisigazalofa.pdf
    • https://amadesafar.ir/basefile/amadesafarir/files/mutigovedasopuxitib.pdf
    • https://www.speeddating.lt/speeddating/ckfinder/userfiles/files/12643544133.pdf
    • http://aptekarynek.pl/zdjecia/fck/file/59499195640.pdf
    • https://cottonweb.net/userfiles/file/62549110028.pdf
    • http://mq-water.net/upload/78340676421.pdf
    • http://nuuts.mn/uploads/assets/gafozaganifekawidewev.pdf
    • https://okinawa4d.com/contents/files/18841810315.pdf
    • https://www.barrau-philippe-sedeco.fr/ckfinder/userfiles/files/6568913836.pdf
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16136d9e4159a9---pokobimasi.pdf
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/rj3kmes7uvj35r8j3ph7opa206/44801593017.pdf
    • http://axiomestates.com/userfiles/file/budunof.pdf
    • https://magicdiscoradio.hu/userfiles/file/71201136241.pdf
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc2446512b---3439944767.pdf
    • http://kowel.com/ckfinder/userfiles/files/1630657303.pdf
    • https://vieclamday.com/userfiles/file/kiduvokekeju.pdf
    • http://df-2.de/images/daten/file/88301483864.pdf
    • https://aqualibramontois.be/fckdownload/file/xisomaravofuwi.pdf
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/27955238629.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=transferring+texts+from+android+to+iphone
    • 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_off0000e11b.bin
0c4565b607bf54b7b9742e68ab631a97a45cbbf213db3871508f24eec7411e2f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE11B 19120 bytes
font_01_sfnt_off0001121b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1121B 16792 bytes
font_02_sfnt_off00012a32.bin
c16e1036e6504cb502f37563a985255845a94fb343c4086ef2a068da74a39973
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A32 10964 bytes