Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3f87afd877394bc…

MALICIOUS

PDF

70.8 KB Created: 2021-09-21 06:06:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 965b14d2bb72072586179a69d23f0caa SHA-1: 57e3be854472f869c0356bbdcf20fd605bde4f54 SHA-256: b3f87afd877394bc5d99db29a4b6e19e64963c84e46a669cfee74fdfab608a69
156 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple domains, some of which are hosted on compromised WordPress sites or appear to be disposable. The embedded URLs suggest the primary goal is to redirect users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://laborke.ru/uplcv?utm_term=php+print+html+to+pdf PDF link annotation
    • http://azbuka-d.ru/ckfinder/userfiles/files/jiruwesojoxuvunakititav.pdfIn PDF document text
    • https://iasvn.org/Images_upload/files/vokujobajagumudikuwewenub.pdfIn PDF document text
    • https://restaurant-kamkok.fr/img/Data/file/62424870626.pdfIn PDF document text
    • http://image.dlib.vn/libedu/news/bachviet/20210918/file/53259862728.pdfIn PDF document text
    • http://a9188.com/upload_files/art_files/files/20210910_150445.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/xotizitivetazom.pdfIn PDF document text
    • http://rancholasmonturaspremios.com/campannas/file/48675659180.pdfIn PDF document text
    • https://quangcaowebsite.xemlaco.com/uploads/files/97453908857.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/kaganuxinisarine.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/sekisekaxekomabopemaxe.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/si2n3if954oj7jkid6aa6jc0f0/borazixoteni.pdfIn PDF document text
    • https://shreenatharcade.com/userfiles/file/titibilidexupunawizuxamu.pdfIn PDF document text
    • https://globalathena.com/ckfinder/userfiles/files/dubadupadobadipe.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130f2edc030f---14424419640.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/85947212473.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/91386590928.pdfIn PDF document text
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/jutufapuxejoxakiw.pdfIn PDF document text
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/zewonoda.pdfIn PDF document text
    • http://aa-nusd.jp/zifajupekazo.pdfIn PDF document text
    • http://maradonasalud.com.ar/ckeditor/ckfinder/userfiles/files/81259227882.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4dbdab3ec---bazigefunotuloxexeded.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/44bc4c22c5dd8aa203e10cfa0fb22580/neripitakit.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_off0000b4a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4A1 16472 bytes
SHA-256: 962858a2fcd7de4c6bb65cb644edd2f24d5fe4450aab94e0d7af530e9fb9a2de
font_01_sfnt_off0000dee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF700 10304 bytes
SHA-256: 3b2841b08a28c3e128fb5abb4192480db65bf10ea282782e2c07595576b77694