Malicious PDF — malware analysis report

Static analysis result for SHA-256 91156e4769c4260c…

MALICIOUS

PDF

70.2 KB Created: 2021-10-03 04:08:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1ef96253fa1e243eaed8a8637ee40486 SHA-1: 43f3695e2b24ff00d1d8f924af93155c01ae3830 SHA-256: 91156e4769c4260c31c0b85e47e185061bbfe9169f86531b62bde5499fdfec29
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to potentially compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of multiple external URIs and link farm heuristics supports the classification as a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://inwebjor.ru/uplcv?utm_term=self+introduction+message PDF link annotation
    • http://trungtamdaykem.vn/Images_upload/files/12818300720.pdfIn PDF document text
    • http://viswinkelindex.nl/images/uploads/fijapibitololulogazavam.pdfIn PDF document text
    • http://wdnederland.nl/file/tululoroxurabaj.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/63078182276.pdfIn PDF document text
    • https://scalping.ir/data/files/file/79172273007.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615416183742e---16670910390.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/pediviwedi.pdfIn PDF document text
    • http://columb-sklep.pl/userfiles/file/norodazufugan.pdfIn PDF document text
    • http://bettynblue.com/upload/fck_img/20210927/file/gatagavizudaledax.pdfIn PDF document text
    • http://lactopad.com/uploads/files/36702475953.pdfIn PDF document text
    • http://gyn-ordi.at/myPix/file/musujajivexefemuvob.pdfIn PDF document text
    • https://semsaesp.com/ckfinder/userfiles/files/bikezikeburokafepojupu.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16131d4c2eb407---25488473494.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210905134406.pdfIn PDF document text
    • https://jajugroup.com/ckfinder/userfiles/files/vubamasiroran.pdfIn PDF document text
    • http://prvugkh.ru/uploads/files/naxikozelozagop.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613fda05465c6---40074439063.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/gabololodutijagabokepiko.pdfIn PDF document text
    • http://xboxheerlen.nl/userfiles/file/lopesapola.pdfIn PDF document text
    • https://piti.leaddeehub.com/userfiles/files/67040723461.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613059c1c20b5---nanituvigewusone.pdfIn PDF document text
    • https://sweetburden.com/upload/users/files/podizo.pdfIn PDF document text
    • http://forum-auto.ru/data/files/69557366084.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_off0000af2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF2B 10996 bytes
SHA-256: 02b06e18fa8685df70f270ef1f37e5fdac88a9ea83ae03ac53b06bcbbcdaf449
font_01_sfnt_off0000c870.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC870 17072 bytes
SHA-256: 05194d072fa2cbe7790311ff5a351b5b65d93438d554563a0110f8e28513828f
font_02_sfnt_off0000f3a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1