Malicious PDF — malware analysis report

Static analysis result for SHA-256 37edc4c22e8d415c…

MALICIOUS

PDF

71.6 KB Created: 2021-09-14 13:03:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 05ee7bba2889949cd606812a96b1bb98 SHA-1: d6e63673aedaf42218f546d8e9559355f69d97f8 SHA-256: 37edc4c22e8d415ce3386095aa3f23d579f0c11791c6d39b63e2dbe2cb36966b
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, containing numerous embedded URLs that point to compromised WordPress sites and other domains. The primary purpose appears to be directing users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 http://www.mecateengenharia.com.br/ckfinder/userfiles/files/lofusimigapu.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/be6caa4d3e715cf22f04b4accc246073/79346476131.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/d685630937b31e4020c41cc496f4aa63/vinexi.pdf
    • http://erisalaw-chicago.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/77152572984.pdf
    • https://soi.icami.mx/ckfinder/userfiles/files/32727661852.pdf
    • http://deaprogettazioni.it/userfiles/files/88601356380.pdf
    • http://kronospan-mofa.hu/editor_up/gareda.pdf
    • http://duoctruongxuan.vn/userfiles/image/file/tedawovoki.pdf
    • http://vesimport.ru/userfiles/file/54395700872.pdf
    • http://ymmicro.com/files/files/29139451783.pdf
    • https://swagath.co/new/ckfinder/userfiles/files/81321821685.pdf
    • https://vishalahospitality.com/ckfinder/userfiles/files/pewijuzebewaje.pdf
    • http://jikaramen.com/uploads/files/75337174588.pdf
    • http://maekuangudomthara.com/ckfinder/userfiles/files/4495236959.pdf
    • https://impactmediaresources.com/userfiles/file/18211913617.pdf
    • http://etnorom.hu/pictures/56995111532.pdf
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/e06051acd1399ca6af012945549a9982/31534052557.pdf
    • http://buyyoutubelikes.com/ci/userfiles/files/vefinoposetedunonire.pdf
    • https://ritascreation.com/userfiles/file/degus.pdf
    • http://longthinhphat.net/uploads/files/563241489.pdf
    • http://apnschool.in/singhania/downloads/file/41176332247.pdf
    • http://xn--q20b13r9leepaeb.net/upload/file/202109020804583485.pdf
    • http://curry-box-deluxe.de/userfiles/file/79764779672.pdf
    • http://virtualcharityevents.com/vce_cake/files/files/30400253259.pdf
    • http://vdadanang.vn/app/webroot/assets/files/23288775518.pdf
    • https://cafesca.info/ckfinder/userfiles/files/bedinaleluzosizexeruzi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=screen+share+pro+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b866.bin
a313e4d00cd1400590bd7a69a9f12e67c4395b03cf32b32e8b8523eca38e8b96
pdf-font-stream PDF embedded font (sfnt) at offset 0xB866 15764 bytes
font_01_sfnt_off0000e09d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE09D 16792 bytes
font_02_sfnt_off0000f8b4.bin
329fec5fe7d108482b5b2cb4eb186e8bca3a2ee15cc7d2758a91329cfeed9acc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B4 10400 bytes