Malicious PDF — malware analysis report

Static analysis result for SHA-256 f74d40a03ca250b5…

MALICIOUS

PDF

70.6 KB Created: 2021-09-18 11:58:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 5f8c2319228c5a618d522cf4d2f70fa0 SHA-1: 1be6378b937443f1eed8aa5e27c0828c88b53337 SHA-256: f74d40a03ca250b52b03dab654921a73b8da1dd6c468b6b7cec3752b32518be7
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of external URIs and link farms points to a spearphishing attachment as the likely initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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=android+system+recovery+download PDF link annotation
    • http://grubstreet.ca/ckfinder/userfiles/files/kugovoluf.pdfIn PDF document text
    • https://promenade-perpignan.com/userfiles/file/87539836214.pdfIn PDF document text
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/89580233298.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/zesepoxisiwivaso.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/91131574466.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/48084946303.pdfIn PDF document text
    • http://tuanlongland.com/upload/files/lukokugeduruvifoganis.pdfIn PDF document text
    • http://businessplan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/movemofepirukabirapexa.pdfIn PDF document text
    • http://saigondome.com/uploads/userfiles/file/77433633087.pdfIn PDF document text
    • http://plenaseguroseprevidencia.com/fotosempresa/files/94025096548.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/df650d0d747cecf3d7e4ae70ab2b6238/32369186431.pdfIn PDF document text
    • https://ltssinternational.com/res/wysiwyg/file/bupoxuzomajejijenofagif.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/d16eb716590d7dc632909c88d8b09aba/71296483607.pdfIn PDF document text
    • https://kawanmto.info/contents/files/22313953305.pdfIn PDF document text
    • https://ms02bet.net/contents/files/61260608331.pdfIn PDF document text
    • https://laznia-radom.pl/userfiles/file/13918213551.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/bobelumav.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/sutifemijubapebifu.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/52725282958.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614038b52bd65---80181420628.pdfIn 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_off0000b370.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB370 15900 bytes
SHA-256: 991da9342a6f28babbe8d9533121060ebc2bfa5d482e8483f6b253cc5843d18c
font_01_sfnt_off0000dc27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f43e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43E 10780 bytes
SHA-256: f528623812cc29c387cf02246e1dcad52a7fe7d106e18721361a902539aedfa8