Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf42ba6abe6d1146…

MALICIOUS

PDF

76.2 KB Created: 2021-09-19 23:50:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0718c22787203e0e28ba1a2e84375fcb SHA-1: ae1a8edb50a27dbab80ac3daf53f76e4f570cdce SHA-256: bf42ba6abe6d114653f22790ffdbe3e6f8b9187f26506896e71c6afbb1ce1377
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs that point to other PDF files hosted on various domains, many of which are flagged as compromised or disposable. This structure suggests a link farm designed to distribute malicious content or manipulate search engine results. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://szyldkj.com/luodan/images/userfiles/file/forebos.pdf In PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/42041464523.pdfIn PDF document text
    • https://kangaroovietuc.vn/webroot/img/files/27362934696.pdfIn PDF document text
    • http://clarksville.net/wysiwygfiles/file/pupusidufu.pdfIn PDF document text
    • https://pustelnik-budownictwo.pl/ckfinder/userfiles/files/61162559348.pdfIn PDF document text
    • http://itemclinicchina.com/ckupload/files/wajitexa.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/92408625717.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/h87heqpq99e2gsoo0pso05rubt/38558086752.pdfIn PDF document text
    • http://lacasedescaraibes.fr/file/rilisetovijiko.pdfIn PDF document text
    • https://vialivonica.eu/userfiles/files/xawojibabogufojej.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/f6cce821cd9e187e95ae03a87b1c52c6/turorejalibixabekil.pdfIn PDF document text
    • http://thuonghieutoancau.vn/uploads/files/wasibower.pdfIn PDF document text
    • http://vocal.bpv.su/content/files/files/tebud.pdfIn PDF document text
    • https://raguvosbaldai.manovonia.lt/images/files/89115217433.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/potawolamivolobuwiwupaf.pdfIn PDF document text
    • http://xn--b1agaa2anfqdp.xn--p1ai/ckfinder/userfiles/files/puxetizijan.pdfIn PDF document text
    • https://viessmannboilers.ca/fck_upload/file/rolajadoroli.pdfIn PDF document text
    • http://z-him.ru/userfiles/file/58061325954.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fe389e3c1e---rikomenaletumifiwesiz.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/fufepibuxeriwawi.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/zezatexelajekibefa.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/a8d91276a217d48c18c42e8b1a68076b/66943153096.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+uninstall+secure+hub+from+androidPDF 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_off0000c492.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC492 17536 bytes
SHA-256: b4f7e624566554086d6fcbe2f60619af8e6e2182afa10fc82dd1c0fddf695cae
font_01_sfnt_off0000f207.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF207 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010a1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A1E 11060 bytes
SHA-256: fd0d25f6984917c80b8b68d24b61111283c466039bb32b85bda8c98afc653d06