Malicious PDF — malware analysis report

Static analysis result for SHA-256 a83757f948add41e…

MALICIOUS

PDF

77.5 KB Created: 2021-09-12 06:48:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d970d773e3f126400941e86cc96560ff SHA-1: 925d38032bdf51cc683a72c43fde8f08f1c74e57 SHA-256: a83757f948add41ea0642400dc961379c6daa0a0d389cdf1c94008a4c85fca6a
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and a link farm heuristic points towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://www.logomarcanet.com/userfiles/file/4150196557.pdf In PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/ak2tk4644na95apbk7rh8u1gca/83194864366.pdfIn PDF document text
    • http://fkjz.cn/upload/files/2021/09/202109071525417749.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd37a87b5c---kosibosupadupelerenexagu.pdfIn PDF document text
    • http://arenabilardo.com/data/_files/59224485543.pdfIn PDF document text
    • https://bizimpin.com/calisma2/files/uploads/meriruvuzikogisejevuwobe.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/nobep.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d323a68558---52128000353.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/xodidakiwapapibi.pdfIn PDF document text
    • https://ski-valloire.com/ckfinder/userfiles/files/nimotuko.pdfIn PDF document text
    • https://clifestyle.net/uploades/userfiles/file/16260302626.pdfIn PDF document text
    • http://vocal.bpv.su/content/files/files/tidorumutebo.pdfIn PDF document text
    • http://thesnowmanicecream.com/ckfinder/userfiles/files/7671728735.pdfIn PDF document text
    • https://tepihtrava.rs/files/dadajijuruw.pdfIn PDF document text
    • http://polishingmarblefloor.it/userfiles/files/95068560912.pdfIn PDF document text
    • http://kiuanai.com/userfiles/file/bomiregexira.pdfIn PDF document text
    • http://sushigonewildtogo.com/uploads/files/jifevorotulibulupawe.pdfIn PDF document text
    • https://sgcaregiver.org/contents/files/vowoxitiforekokufame.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138960b1607e---73251545651.pdfIn PDF document text
    • http://tao-oita.com/admin/upload_filesfile/piled.pdfIn PDF document text
    • https://zhansq.cn/upload/file/28812238757.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=go+launcher+prime+apk+full+2020PDF 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_off0000c534.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC534 19116 bytes
SHA-256: 62be0b0f7e39a292d83e5e40d077e9b4d9d3b9c27e433bed29e2b796ae870215
font_01_sfnt_off0000f705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF705 10952 bytes
SHA-256: 23ab1d6dec324738d970467868bc037a70dbe14ea4d9c4eac3f6806716e5093d
font_02_sfnt_off00011037.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11037 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1