Malicious PDF — malware analysis report

Static analysis result for SHA-256 f538f9bad3d261f1…

MALICIOUS

PDF

92.4 KB Created: 2021-09-16 23:33:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: da9d4d67909c991a0ba36c4d956ccbc5 SHA-1: 95d7922897d1b935bbaf1bf06aab6969b44f8cf7 SHA-256: f538f9bad3d261f1d2cae4be4cba197c6d66beec78cb66f6f67b8660af35b4ee
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, several of which point to compromised CMS upload storage, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites or download further malware. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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://signauction.net/userfiles/file/79307505293.pdf In PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/61432258450.pdfIn PDF document text
    • https://ph789.com/pinhsuan/files/file/39677931395.pdfIn PDF document text
    • https://efsanepin.com/calisma2/files/uploads/fusovigi.pdfIn PDF document text
    • https://radio-aurea.eu/files/file/78776736976.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109161456522766.pdfIn PDF document text
    • http://avtosfera28.ru/userfiles/file/65811405782.pdfIn PDF document text
    • http://alvitraders.com/files/41558153923.pdfIn PDF document text
    • https://motoralbini.it/files/file/sagapulas.pdfIn PDF document text
    • https://schmitz.cz/res/file/jedoj.pdfIn PDF document text
    • https://elsadaulte.com/ckfinder/userfiles/files/lulebofuxasub.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161410eed57fb5---71841356462.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/fe319efa9240a0442a31816da48f9596/66081399614.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210913194447_mad68p.pdfIn PDF document text
    • http://recrute.fr/files/files/rozipunapogomesose.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1613a67865b652---69801400141.pdfIn PDF document text
    • http://myphamasia.net/upload/files/pilumevotixisozulinupido.pdfIn PDF document text
    • https://girl0229960192.com/upload/users/files/jipaxugagumaxawetulu.pdfIn PDF document text
    • https://cfi-registration.amyhalter.com/buzzboxgift/img/userfiles/files/fivuvagodadugitepojavapet.pdfIn PDF document text
    • http://xn----otbbfbbknchz.xn--p1ai/sadm_files/rolejatoxogilokug.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/panumaxepazunijerasosavu.pdfIn PDF document text
    • http://80tner.netsociality.com/upload/files/suzimedabagasajovofo.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613da778d996f---tudet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=best+spoofing+app+for+pokemon+go+2021PDF 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_off000101e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E0 18344 bytes
SHA-256: 43255d712b966eed361363ebef896d195786a440c822b62c497b8384f852e5dd
font_01_sfnt_off000131b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000149d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149D0 11092 bytes
SHA-256: b440a24b17a531f9e363ce2867e2acc87fc58991e2807d4109cc4aa501a4fbbd