Malicious PDF — malware analysis report

Static analysis result for SHA-256 912cbea8f9973e3e…

MALICIOUS

PDF

75.4 KB Created: 2021-09-15 23:38:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b47c0c65f59f5aacab2ff0288475e0f6 SHA-1: 40dd27fa0ee72cd35e7c629b1ac1c2e3cb55c3c2 SHA-256: 912cbea8f9973e3e756322e1f59d453519cbc0f69c6bd77a110e2dea1ab26597
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various websites. Several of these URLs are hosted on compromised CMS uploads or disposable domains, suggesting an attempt to distribute malicious content or engage in SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://qdsenfeng.com/data/files/26584783560.pdf In PDF document text
    • https://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/74945787448.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/1d136170126decbaad7d36001655637b/82322790627.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a4df2c6e3---mipidigogevevole.pdfIn PDF document text
    • http://nghieuphong.com/upload/files/gibimixosanumif.pdfIn PDF document text
    • http://champaigncursillo.com/userfiles/file/xagimojeguwidilusalaz.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/09111bf771e15afb3aefc481ad311d01/95549552222.pdfIn PDF document text
    • https://unitytradecapital.com/ckfinder/userfiles/files/xowiwedugegov.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/202197222342277.pdfIn PDF document text
    • https://bostaninsaat.com/image/files/wesalu.pdfIn PDF document text
    • https://petribax.com/userfiles/file/xekejidubopiredoviredix.pdfIn PDF document text
    • http://premiumcsp.com/uploads/files/21357225090.pdfIn PDF document text
    • https://pinyardim.com/calisma2/files/uploads/87050041390.pdfIn PDF document text
    • https://mytopics.it/uploads/file/sezasagiwowuparatopaxipop.pdfIn PDF document text
    • http://dsraxys.com/uploads/busaro.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/kikafatumeku.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/6c105fc7bec6b90869da94b131d84bf6/85023123676.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1630483036.pdfIn PDF document text
    • http://strategie-online.net/catalogue_dynamique/file/93347183347.pdfIn PDF document text
    • https://tungafilm.com/dorceiys/ckfinder/userfiles/files/poxuvetowep.pdfIn PDF document text
    • https://jdrum-music.com/uploads/ckfiles/files/20114180708.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=the+rate+of+reaction+increases+to+2.3+timesPDF link annotation
    • 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_off0000c09d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC09D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AF 17488 bytes
SHA-256: dd243e15b602e8af243633af36360e327237fa0f0e2434f977e665f4e450b2db
font_02_sfnt_off0001067d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067D 10876 bytes
SHA-256: b11baec891a8a02080f9b2d98d63636d74c274a9831df60712e76b9505d7c2dd