Malicious PDF — malware analysis report

Static analysis result for SHA-256 33c030e37526b343…

MALICIOUS

PDF

92.4 KB Created: 2021-08-05 01:24:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 50fdceb4e250dc1e41e2bed86bb0a401 SHA-1: 28ebeccad32012c46736d64f7886a74b5f5672fe SHA-256: 33c030e37526b343fc21b5e46742012bc8e5368a44246fcc3ac5fb3decf473f4
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload storage and disposable hosting, suggesting it functions as a link farm to distribute further malicious content or phish for information. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://chroscina.com/userfiles/file/konafenovizegabojuxo.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/482007a3caf3c4d6dea686bf802d5033/3980816446.pdf
    • https://fier-forjat-valimet.ro/ckfinder/userfiles/files/redokaguwewipaxo.pdf
    • http://ldbell1965.net/clients/85689/File/36138730104.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/b8dd4a3a33364ef16d7b99a97c9a03bc/34327637954.pdf
    • http://k-sta.kr/FileData/ckfinder/files/20210720_1DADB2CBEA962515.pdf
    • http://bannermaul.com/userData/board/file/3144763986.pdf
    • http://vinmexindia.com/uploads/kiruregazanutev.pdf
    • http://stlukesmn.org/clients/17773/File/lolusesajuxagarejo.pdf
    • http://www.firengo.com/userfiles/files/liredajevogamebif.pdf
    • http://richfield1960.com/clients/865265/File/79223280243.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d79cdb72252---79011879759.pdf
    • https://yingzhaoliuart.com/upload/file/lufegubekesetu.pdf
    • https://detectiveoffice.net/userfiles/file/60959838830.pdf
    • https://grupo-bahia-real-estate.com/ckfinder/userfiles/files/42951962451.pdf
    • http://goodslib.com/userfiles/files/wazuxuvakiserovakab.pdf
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/7e0b6baf678c37189463b479903c3e29/nuzemujogivi.pdf
    • http://edv-denk.com/userfiles/file/jelilofulononabuno.pdf
    • http://kag.fr/userfiles/file/25295204127.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c6f34a548154ce0365053b639ba512c4/60547940287.pdf
    • http://angelofthewinds.org/ckfinder/userfiles/files/98408112008.pdf
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/c9b5d6cbe32fe01656627e8beafc1ba1/1666292451.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+setup+a+netgear+n300+wifi+range+extender
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e79d.bin
873de5a920267880cc56ff96cf4a1d4af62835d26a07bfeb5c6c9dfab6ea7a9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE79D 16928 bytes
font_01_sfnt_off000113ae.bin
55bd30fb548f55989f025e6880283b760592eb4fb772637ed35e9de21a0fd3a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x113AE 11200 bytes
font_02_sfnt_off00012de8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE8 16792 bytes
font_03_sfnt_off000145f9.bin
16ef6c97139397662582d19f5c81e78cd103b396be0da0ff7a3eb74d00fcef32
pdf-font-stream PDF embedded font (sfnt) at offset 0x145F9 18276 bytes