Malicious PDF — malware analysis report

Static analysis result for SHA-256 a539fff7ac7428e3…

MALICIOUS

PDF

83.2 KB Created: 2021-07-12 22:16:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 303ea75dd080e7404a975d08303039af SHA-1: c6614318798bc68cf858f2410c17cdaa7d339274 SHA-256: a539fff7ac7428e3e73103aa782c6331ac525c6c4654676e131476cff079abcb
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, likely to lure users into downloading further malware or engaging in phishing activities. The presence of multiple compromised CMS upload links suggests a coordinated effort to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://philabc.ru/uplcv?utm_term=7th+class+maths+worksheets+pdf PDF link annotation
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/agd0su5eargjliitlvoc5cffm5/rovilobatiberabo.pdfIn PDF document text
    • http://chanakol.com/ckfinder/userfiles/files/bulosegozili.pdfIn PDF document text
    • https://aviseco.ro/userfiles/file/digokekoturixutivajaxix.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc38d73b96---17084509180.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/taxipik.pdfIn PDF document text
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/e0f158800d8fc430038d09a061d8cfbc/safumumujeburejisajuzos.pdfIn PDF document text
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/tm4823monp38l6bt5t85c1sdeo/vasifajigowiwakikasi.pdfIn PDF document text
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210616042011.pdfIn PDF document text
    • http://bettynblue.com/upload/fck_img/20210603/file/kagoviguzutemanatifulet.pdfIn PDF document text
    • https://deltagroup.bg/uploads/file/mibawoworuwepozifekasugud.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160794ff458c31---kugako.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/60460330459.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/40a008abb580097a47c89cdf58817fb7/kogov.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a163ae512acf58df5ac7d877881a6763/garuratilex.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/repemurowesajo.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/52871238305.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087973c5b582---70139149911.pdfIn PDF document text
    • http://china-hold.com/UploadFile/file/20210522051240169.pdfIn PDF document text
    • http://esthebel.de/userfiles/file/95447913041.pdfIn PDF document text
    • https://langumeistras.lt/i/File/27202575700.pdfIn PDF document text
    • https://walkandsmile.com/userfiles/file/ximedobufabonen.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/51645e0a08dc2a69a6fb5ded12d60274/50319458945.pdfIn PDF document text
    • https://atraba-holding.com/userfiles/file/86197711972.pdfIn PDF document text
    • https://termofriz.rs//files/vosuzuvuledubi.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_off0000e0f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0F1 10820 bytes
SHA-256: 22d4dc43beedc9a84d181fa7699e8bf31b86afd33c8259b337c8bf0671df2839
font_01_sfnt_off0000fa11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA11 17656 bytes
SHA-256: 81d97861a7dba658a90e594b810703fa2e83480ba44f29e35b8ff30f888c4faa
font_02_sfnt_off00012766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12766 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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