Malicious PDF — malware analysis report

Static analysis result for SHA-256 57140fd92a366585…

MALICIOUS

PDF

107.5 KB Created: 2021-06-25 13:52:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 37e6912729abe6a4eabbd2afbe8d71ee SHA-1: 686f0151c0359e63ff2752871040b46f62e56259 SHA-256: 57140fd92a36658581fce3175614850f637dd48cac54b3ff20befc4fe791a3f8
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics as malicious, including ML classification and ClamAV detection. It contains numerous links to external sites, many hosted on compromised WordPress installations, suggesting a phishing or malware distribution campaign. The presence of invoice and callback lures indicates a social engineering attempt to trick the user into clicking the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://ketchas.ru/uplcv?utm_term=please+see+attached+files+for+your+reference
    • http://pogservice.ru/userfiles/file/72114820228.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085bc54461aa---pefafipavosorafinakure.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d04bfb1e03---mogunogibizuwe.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d51526ad5c---gawekiguxafetorisopikit.pdf
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbd2a3d9a1---suwenuvoxod.pdf
    • https://thinkhigh-tech.com/d/files/97218784488.pdf
    • http://futurepoolandspa.com/ckfinder/userfiles/files/68281840879.pdf
    • http://www.findvoters.com/userfiles/file/rosutebugovivikogome.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160aa7dc21996c---80399328199.pdf
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e97276e5b3---23692174423.pdf
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/jpq03900j2ar34cgrjtj68dlbu/vilimivewesenib.pdf
    • https://acgroupenterprise.com/userfiles/file/rewizewomadamubegaru.pdf
    • http://www.pattyn360.com/upload/forum/files/bupezimogatofitewuk.pdf
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/12a01701303cc1f4ff2359e8ed23b167/wulujapuladusi.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_off00013cc9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13CC9 16792 bytes
font_01_sfnt_off000154db.bin
92f0769a11c1498913940f46228abb57b99bff5933685cc1ade8a87fc865fb21
pdf-font-stream PDF embedded font (sfnt) at offset 0x154DB 19952 bytes
font_02_sfnt_off00018878.bin
dab9ebb684b4d8418d22e7f2e069d9763c5a19d6ea58ea09442027774bf5bca0
pdf-font-stream PDF embedded font (sfnt) at offset 0x18878 10788 bytes