Malicious PDF — malware analysis report

Static analysis result for SHA-256 98d7bc1caf50f61c…

MALICIOUS

PDF

73.8 KB Created: 2021-08-28 02:46:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5b470b8cd9426d7777932ae6297ab9e1 SHA-1: a4ad1260d1da14fcc13010c177d667622525244e SHA-256: 98d7bc1caf50f61cbd85c289bad509648b173256e1f2c59e65296b3285ea45e6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

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, with many URLs pointing to compromised websites or disposable domains, suggesting it's used for phishing or distributing further malware. The PDF structure itself does not contain executable content, but the embedded links are the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://krisoc.ru/uplcv?utm_term=how+many+grams+in+one+pint
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/juvovog.pdf
    • https://cesiedizioni.com/userfiles/file/44501844632.pdf
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074c9896d79e---wesobefagoda.pdf
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160aae22e2e526---68249921658.pdf
    • http://adabaskimerkezi.com/upload/file/javunagukana.pdf
    • http://zdrowejaja.com/Upload/file/jefotebomemoramavudeviwam.pdf
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/l7hrnnqr2jol7jm5jmiot4k7kh/winesagulanamekatu.pdf
    • https://alixdemassy.fr/userfiles/file/pikogawujepobojiwofumu.pdf
    • https://llibreriaha.com/img/events/file/26827171437.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf86148dad---mipejifezoxumumofimowaj.pdf
    • http://ctmmaximoravenna.com/ckfinder/userfiles/files/muxafupopofapuvatosora.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/sfe3kcsn748c35d390sego6ei0/26071856116.pdf
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095d14895521---difewavetazefevetulez.pdf
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/aeb31d5ec23686319081f5f0933a169f/11527416501.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/e9827cbbc512316d5c2ac8dace232ca5/pikunozomigowofo.pdf
    • http://jorkurojus.com/userfiles/file/tojulizuxuguwudedamufota.pdf
    • http://mayingiabao.com/upload/files/gulogubava.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160a518410bbc7---pajinegefi.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085a39cb0844---reledutat.pdf
    • https://aviseco.ro/userfiles/file/fumijuxegumo.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/80bb20ecff37c330cf19f24c2d8d4956/zudufeparikugemuzu.pdf
    • http://kleinschaden-expert.de/userfiles/file/lapunakekozebiwosobujowi.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160de9c7c492b4---zifaju.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_off0000bec7.bin
51a8b7da146f0cd0c4fa00d0c20a747ed8f208970b32f8749b9a8d261d102e17
pdf-font-stream PDF embedded font (sfnt) at offset 0xBEC7 10740 bytes
font_01_sfnt_off0000d782.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD782 16792 bytes
font_02_sfnt_off0000ef94.bin
be21c978be35513b5bd279e8d6854de4f25e0030a316dd4d65a32b1127e21e28
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF94 16424 bytes