Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac187f78e13f4e00…

MALICIOUS

PDF

83.5 KB Created: 2021-09-16 13:57:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d2d1e2c26bb091a4b1806f80035e1caa SHA-1: 81b45b959580012138b548a5a0e2363fad6a120d SHA-256: ac187f78e13f4e0008f90b1466a708259458a2ce66e029a1f92d37dadd227896
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document that contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and numerous external links suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=android+gamer+com PDF link annotation
    • http://market-oborudovanie.ru/upload/file/pilowesisixivu.pdfIn PDF document text
    • http://amkchem.com/upload/files/jusexumubofububek.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/xuvefukabuvakudozebazisap.pdfIn PDF document text
    • http://tccsrl.org/userfiles/files/2560249524.pdfIn PDF document text
    • http://uhorder.com/upload/files/lugolisutubunefevaguwa.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/jiwaligi.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/46181379862.pdfIn PDF document text
    • http://isvpro.com/custom/files/77232194997.pdfIn PDF document text
    • https://falconshipping-uae.com/userfiles/files/6575307315.pdfIn PDF document text
    • http://e-skala.pl/userfiles/file/watawukinijijowosumetuw.pdfIn PDF document text
    • http://hagelkonzept.de/userfiles/file/mibubikixebofeje.pdfIn PDF document text
    • https://yaofangpeixun.com/upload/files/nilata.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613badd46cab1---96686726154.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/72830965424.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/riwazodasavizipivos.pdfIn PDF document text
    • http://bk-plus.at/userfiles/files/gudobipijupuwad.pdfIn PDF document text
    • http://ceresasrl.it/userfiles/files/99620742494.pdfIn PDF document text
    • https://aynispirit.nl/userfiles/file/mupigun.pdfIn PDF document text
    • http://covina.crazyrockinsushi.com/uploads/files/zamezo.pdfIn PDF document text
    • http://wowbond.com/upload/Fckeditor/file/17207726145.pdfIn PDF document text
    • http://ipost.mn/ckfinder/userfiles/files/lumofunemabudavoku.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16136de4340ab9---4946031896.pdfIn PDF document text
    • http://sangtaoad.com/uploads/userfiles/file/50330090106.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/riwigalepizimidiw.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/19232083001.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_off0000e161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE161 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f978.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF978 10380 bytes
SHA-256: d0e4cddde30f53ba9d9c992a61cd011595ff0eefe68eebe44be629928cd1ce73
font_02_sfnt_off000110ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110AD 18432 bytes
SHA-256: d24602adc4dee558714db45459fa31339bc7d96334ca63e7ab38c04e36da5b0f