Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b18a4772060b33…

MALICIOUS

PDF

76.4 KB Created: 2021-09-06 20:46:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2f90ae8df080992762cf3430da8f79f0 SHA-1: aa4ee2439e94118c5f72c07d20eecead1429e9c4 SHA-256: 83b18a4772060b337c8a068abda43c0e09e300c228bdd1fdbcdc0a6d1b84968c
196 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on compromised websites, directing users to download what is likely a password-protected archive. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' strongly suggests the document's intent is to trick the user into downloading an archive and then providing a password, a common tactic to bypass gateway security. The ML classifier and ClamAV detection further confirm its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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 http://peak-experience-japan.com/images/blog/file/42971233292.pdf In PDF document text
    • http://kor-ra.ru/UserFiles/file/37291900700.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/99597146680.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/8318141340.pdfIn PDF document text
    • https://designcoordinators.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae63fefffc---84429261237.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d1c86b031fa---85227445596.pdfIn PDF document text
    • http://short-story.ru/upload/file/pileweponepakijoxemoral.pdfIn PDF document text
    • http://recviem.ru/img/upload/14232050391.pdfIn PDF document text
    • http://wellfoto.cz/pictures/files/pexafofokevum.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/7149386024.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607036d8d3ab4---6561106467.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/13d932bb85be947b0285b1bda6e91594/73696266084.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/pigakodu.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e169ecd53d---64484319085.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/21025283452.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160860e31f1a54---9413347955.pdfIn PDF document text
    • http://harissarantis.com/userfiles/files/kerowalozonileduxerowokam.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c388b3bde6b---todafo.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1ab740d90---xomasiladutig.pdfIn PDF document text
    • http://papaicountrylodge-longstay.com/user_img/files/18224024604.pdfIn PDF document text
    • https://www.moxiclear.com.au/application/third_party/ckfinder/userfiles/files/66514040617.pdfIn PDF document text
    • http://shangrilayunnan.com/ckfinder/userfiles/files/nuruxifijeliz.pdfIn PDF document text
    • http://rana-international.com/userfiles/files/71992946243.pdfIn PDF document text
    • http://www.fotolia.com&#39In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=jtd5000snss+installation+manualPDF link annotation
    • http://www.fotolia.comIn 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_off0000c802.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC802 16756 bytes
SHA-256: e5a95ef47c89a542b66102b6a9d9f6f69d2d879f00288a401e00d0443a3d82b3
font_01_sfnt_off0000f3c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010bdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDD 10524 bytes
SHA-256: 32312b4360d52a58eee36edd08ac8f4a1ffd30692056bf35dc825801013c04a6